A small script demonstrating how to authenticate with MS Graph and update redirect uris for an application.

Set-AppReplyUrlMSGraph.ps1

<#
.SYNOPSIS
This script demonstrates how to authenticate with the Microsoft Graph and update the redirect uris for an app registration

Requirements:

1. Register an application in the tenant (management app)
2. Grant the app the following API permissions:
	- Application.ReadWrite.All

.PARAMETER MgmtAppId
The ID of the management app which has the proper API permission scopes to perform the action.

.PARAMETER MgmtAppClientSecret
The client secret for the management app

.PARAMETER TenantId
The tenant id for the Azure AD/B2C tenant where the apps are stored

.PARAMETER AppId
The app id of the application where redirect uris should be modified

.PARAMETER RedirectUris
Specify the redirect uris as a string array.
#>
param (
	[Parameter(Mandatory)]
	[string]
	$MgmtAppId,

	[Parameter(Mandatory)]
	[string]
	$MgmtAppClientSecret,

	[Parameter(Mandatory)]
	[string]
	$TenantId,

	[Parameter(Mandatory)]
	[string]
	$AppId,

	[Parameter(Mandatory)]
	[string[]]
	$RedirectUris
)

$graphBaseUrl = "https://graph.microsoft.com/v1.0/"
$loginUrl = "https://login.microsoftonline.com/$TenantId/oauth2/v2.0/token"

$body = @{
	client_id = $AppId
	client_secret = $ClientSecret
	scope = "https://graph.microsoft.com/.default"
	grant_type = "client_credentials"
}

Write-Host "Authenticating with MS Graph"
$authResponse = Invoke-RestMethod `
	-Method Post `
	-Uri $loginUrl `
	-Body $body `
	-ContentType "application/x-www-form-urlencoded"

$tokenType = $authResponse.token_type
$accessToken = $authResponse.access_token

$restHeader = @{
	Authorization = "$tokenType $accessToken"
}

$redirectUrisBody = "{`"web`":{`"redirectUris`":[`"$($RedirectUris -join '","')`"]}}"

Write-Host "Update application $AppId with new redirect urls"
$patchResponse = Invoke-RestMethod `
	-Uri "$graphBaseUrl/applications/$AppObjectId" `
	-Headers $restHeader `
	-ContentType "application/json" `
	-Method Patch `
	-Body $redirectUrisBody