Create-AzureApplication.ps1

# Check if the Azure AD PowerShell module has already been loaded.
if ( ! ( Get-Module AzureAD ) ) {
    # Check if the Azure AD PowerShell module is installed.
    if ( Get-Module -ListAvailable -Name AzureAD ) {
        # The Azure AD PowerShell module is not load and it is installed. This module must be loaded for other operations performed by this script.
        Write-Host -ForegroundColor Green "Loading the Azure AD PowerShell module..."
        Import-Module AzureAD
    } else {
        Install-Module AzureAD
    }
}

try {
    Write-Host -ForegroundColor Green "When prompted please enter the appropriate credentials..."
    Connect-AzureAD
} catch [Microsoft.Azure.Common.Authentication.AadAuthenticationCanceledException] {
    # The authentication attempt was canceled by the end-user. Execution of the script should be halted.
    Write-Host -ForegroundColor Yellow "The authentication attempt was canceled."
    Exit
} catch {
    # An unexpected error has occurred. The end-user should be notified so that the appropriate action can be taken.
    Write-Error "An unexpected error has occurred. Please review the following error message and try again." `
        "$($Error[0].Exception)"
}

#You can choose your own application name here
$DisplayName = "Intune Graph App auth"
$AppReplyURI = "https://localhost"

$graphAppAccess = [Microsoft.Open.AzureAD.Model.RequiredResourceAccess]@{
    ResourceAppId = "00000003-0000-0000-c000-000000000000";
    ResourceAccess =
        [Microsoft.Open.AzureAD.Model.ResourceAccess]@{
            Id = "06a5fe6d-c49d-46a7-b082-56b1b14103c7";
            Type = "Role"},
        [Microsoft.Open.AzureAD.Model.ResourceAccess]@{
            Id = "5ac13192-7ace-4fcf-b828-1a26f28068ee";
            Type = "Role"},
        [Microsoft.Open.AzureAD.Model.ResourceAccess]@{
            Id = "7ab1d382-f21e-4acd-a863-ba3e13f7da61";
            Type = "Role"}
}

Write-Host -ForegroundColor Green "Creating the Azure AD application and related resources..."

if(!($App = Get-AzureADApplication -Filter "DisplayName eq '$($DisplayName)'"  -ErrorAction SilentlyContinue))
{
    $App = New-AzureADApplication -AvailableToOtherTenants $true -DisplayName $DisplayName -RequiredResourceAccess $graphAppAccess -ReplyUrls @("$AppReplyURI")
}
$password = New-AzureADApplicationPasswordCredential -ObjectId $app.ObjectId
$ApplicationId = $($app.AppId)
$ApplicationSecret = $($password.Value)

Write-Host "ApplicationId       = $ApplicationId "
Write-Host "ApplicationSecret   = $ApplicationSecret"