Lua Requires Chilkat v9.5.0.67+
Outlook -- Create Map of Folder Paths to IDs

Recursively descends folders and creates a hashtable of folder paths to IDs. This can be done once at the start of your program (or even less if the map is persisted to a file or database).
The reason this is necessary is because folder ID's need to be passed to the Outlook API, and an application will typically be working with folder paths.
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Lua
local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

local http = chilkat.Http.new()

-- Our folder path --> ID map will be stored in this hash table.
local folderMap = chilkat.Hashtable.new()

-- Use your previously obtained access token here:
-- See the following examples for getting an access token:
--    Get Microsoft Graph OAuth2 Access Token (Azure AD v2.0 Endpoint).
--    Get Microsoft Graph OAuth2 Access Token (Azure AD Endpoint).
--    Refresh Access Token (Azure AD v2.0 Endpoint).
--    Refresh Access Token (Azure AD Endpoint).

http.auth_token = "MICROSOFT_GRAPH_ACCESS_TOKEN"

local sbResponse = chilkat.StringBuilder.new()

-- Begin by getting the top-level folders.
http:clear_url_vars()
http:set_url_var("userPrincipalName", "chilkatsoft@outlook.com")
local success = http:quick_get_sb("https://graph.microsoft.com/v1.0/users/{$userPrincipalName}/mailFolders", sbResponse)
if (not success) and (http.last_status == 0) then
    print(http.last_error_text)
    return
end

local json = chilkat.JsonObject.new()
json:load_sb(sbResponse)
json.emit_compact = false

print("Status code = " .. http.last_status)
if http.last_status ~= 200 then
    print(json:emit())
    print("Failed.")
end

-- This is our queue/stack of unprocessed folder ID's
-- The recursive nature of this example is that we get the
-- child folders for each folder ID in the idQueue, which may
-- cause additional ID's to be added.  We continue  until the idQueue
-- is empty.
local idQueue = chilkat.StringArray.new()

local sbFolderPath = chilkat.StringBuilder.new()
local sbQueueEntry = chilkat.StringBuilder.new()
local folderName = ""
local folderPath = ""
local folderId = ""

-- Prime the map and idQueue with the top-level folders.
local i = 0
local numFolders = json:size_of_array("value")
while i < numFolders do
    json.i = i
    folderName = json:string_of("value[i].displayName")
    folderId = json:string_of("value[i].id")
    sbFolderPath:set_string("/")
    sbFolderPath:append(folderName)
    folderPath = sbFolderPath:get_as_string()
    folderMap:add_str(folderPath, folderId)
    print(folderPath .. " --> " .. folderId)

    -- Push the folder path + id onto the idQueue.
    sbQueueEntry:clear()
    sbQueueEntry:set_nth(0, folderPath, "|", false, false)
    sbQueueEntry:set_nth(1, folderId, "|", false, false)
    idQueue:append(sbQueueEntry:get_as_string())
    i = i + 1
end

-- Initial output:
-- /Archive --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAG8XunwAAAA=
-- /Deleted Items --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEKAAAA
-- /Drafts --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEPAAAA
-- /Inbox --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEMAAAA
-- /Junk Email --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEiAAAA
-- /Outbox --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgELAAAA
-- /Sent Items --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEJAAAA
--

-- Process the idQueue until it becomes empty.  This is the recursive loop.
local parentFolderPath = ""
local parentFolderId = ""
while idQueue.length > 0 do
    sbQueueEntry:set_string(idQueue:get_string(0))
    idQueue:remove_at(0)

    parentFolderPath = sbQueueEntry:get_nth(0, "|", false, false)
    parentFolderId = sbQueueEntry:get_nth(1, "|", false, false)

    http:set_url_var("id", parentFolderId)
    success = http:quick_get_sb("https://graph.microsoft.com/v1.0/users/{$userPrincipalName}/mailFolders/{$id}/childFolders", sbResponse)
    if (not success) and (http.last_status == 0) then
        print(http.last_error_text)
        return
    end

    json:load_sb(sbResponse)
    if http.last_status ~= 200 then
        print("Status code = " .. http.last_status)
        print(json:emit())
        print("Failed.")
    end

    i = 0
    numFolders = json:size_of_array("value")
    while i < numFolders do
        json.i = i
        folderName = json:string_of("value[i].displayName")
        folderId = json:string_of("value[i].id")
        sbFolderPath:set_string(parentFolderPath)
        sbFolderPath:append("/")
        sbFolderPath:append(folderName)
        folderPath = sbFolderPath:get_as_string()
        folderMap:add_str(folderPath, folderId)
        print(folderPath .. " --> " .. folderId)

        -- Push the folder path + id onto the idQueue.
        sbQueueEntry:clear()
        sbQueueEntry:set_nth(0, folderPath, "|", false, false)
        sbQueueEntry:set_nth(1, folderId, "|", false, false)
        idQueue:append(sbQueueEntry:get_as_string())
        i = i + 1
    end
end

-- The hash table of mail folder paths --> ID's can be persisted to XML and saved to a file or database (or anywhere..)
local sbFolderMapXml = chilkat.StringBuilder.new()
folderMap:to_xml_sb(sbFolderMapXml)
sbFolderMapXml:write_file("qa_data/outlook/folderMap.xml", "utf-8", false)

-- The hash table can be restored from the serialized XML like this:
local ht2 = chilkat.Hashtable.new()
local sb2 = chilkat.StringBuilder.new()
sb2:load_file("qa_data/outlook/folderMap.xml", "utf-8")
ht2:add_from_xml_sb(sb2)

-- What's the ID for the folder "/Inbox/abc/subFolderA" ?
print("id for /Inbox/abc/subFolderA = " .. ht2:lookup_str("/Inbox/abc/subFolderA"))

-- Final output:

-- /Archive --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAG8XunwAAAA=
-- /Deleted Items --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEKAAAA
-- /Drafts --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEPAAAA
-- /Inbox --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEMAAAA
-- /Junk Email --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEiAAAA
-- /Outbox --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgELAAAA
-- /Sent Items --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEJAAAA
-- /Inbox/abc --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huv8AAAA=
-- /Inbox/xyz --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwEAAAA=
-- /Inbox/abc/subFolderA --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwAAAQ==
-- /Inbox/abc/subFolderB --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwMAAAA=
-- /Inbox/abc/subFolderA/a --> AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwIAAAA=
--

-- ------------------------------------------------------------------------------------------------------
-- This example applies to: Exchange Online | Office 365 | Hotmail.com | Live.com | MSN.com | Outlook.com | Passport.com
--
-- The Microsoft Graph Outlook Mail API lets you read, create, and send messages and attachments,
-- view and respond to event messages, and manage folders that are secured by Azure Active Directory
-- in Office 365. It also provides the same functionality in Microsoft accounts specifically
-- in these domains: Hotmail.com, Live.com, MSN.com, Outlook.com, and Passport.com.