Creating OAuth Token for Graph API

CreateOAuthAccessToken.ps1

$env:graphApiDemoAppId = "12345678-abcd-efgh-jklm-123456789abc"   # Replace with your Azure AD app id
$env:graphApiDemoAppSecret = "1234567890asdfjk;l54321"            # Replace with your Azure AD app secret
$env:tenantId = "12345678-abcd-efgh-ijkl-987654321wxyz"           # Replace with your Azure AD tenant ID

$oauthUri = "https://login.microsoftonline.com/$env:tenantId/oauth2/v2.0/token"

# Create token request body
$tokenBody = @{
    client_id     = $env:graphApiDemoAppId
    client_secret = $env:graphApiDemoAppSecret
    scope         = "https://graph.microsoft.com/.default"    
    grant_type    = "client_credentials"
}

# Retrieve access token
$tokenRequest = Invoke-RestMethod -Uri $oauthUri -Method POST -ContentType "application/x-www-form-urlencoded" -Body $tokenBody -UseBasicParsing

# Save access token
$accessToken = ($tokenRequest).access_token