I am trying to retrieve the list of APIs each application has permissions amongst other information for.

However the following script gives me empty objects.

Script:

# Get all app registrations in the Azure Active Directory
$appRegistrations = Get-AzureADApplication

# Create an empty array to store app registration data
$appRegistrationData = @()

# Iterate over each app registration
foreach ($appRegistration in $appRegistrations) {
    # Retrieve application client ID
    $clientId = $appRegistration.AppId

    # Retrieve object ID
    $objectId = $appRegistration.ObjectId

    # Retrieve display name
    $displayName = $appRegistration.DisplayName

    # Retrieve API permissions (RequiredResourceAccess)
    $apiPermissions = $appRegistration.RequiredResourceAccess | ConvertTo-Json -Depth 5

    # Retrieve AppRoles, OAuth2Permissions, delegated permissions, and application permissions
    $servicePrincipal = Get-AzureADServicePrincipal -Filter "AppId eq '$clientId'"

    $appRoles = $servicePrincipal.AppRoles | Select-Object -Property *
    $oauth2Permissions = $servicePrincipal.Oauth2Permissions | Select-Object -Property *
    $delegatedPermissions = $servicePrincipal.DelegatedPermissions | Select-Object -Property *
    $applicationPermissions = $servicePrincipal.AppRoles | Where-Object { $_.AllowedMemberTypes -contains "Application" }

    # Add the app registration data to the array
    $appRegistrationData += [PSCustomObject]@{
        DisplayName = $displayName
        ClientId = $clientId
        ObjectId = $objectId
        ApiPermissions = $apiPermissions
        AppRoles = $appRoles
        OAuth2Permissions = $oauth2Permissions
        DelegatedPermissions = $delegatedPermissions
        ApplicationPermissions = $applicationPermissions
    }
}

# Output the app registration data
$appRegistrationData | Format-Table -AutoSize

Output for: DelegatedPermissions and ApplicationPermissions is null