Here is the code that I created but not working.

Define variables, here I created all the variables for the script.

$SourceFolder = "E:\Temp2\PowershellScript\IntuneWin32App-Tool\DummyApp"  # Folder containing the app installer
$SetupFile = "7z2409-x64.msi"              # Name of the installer file
$SetfileName = [System.IO.Path]::GetFileNameWithoutExtension($SetupFile)
$OutputFolder = "E:\Temp2\PowershellScript\IntuneWin32App-Tool\IntuneWin32App_Output\$AppName"       # Folder to save the .intunewin file
$IntuneWinToolPath = "E:\Tools\IntuneWinAppUtil.exe" # Path to IntuneWinAppUtil.exe
#$IconPath = "C:\Path\To\Icon.png"         # Path to the application icon
#$DetectionScriptPath = "C:\Path\To\DetectionScript.ps1" # Path to custom detection script

Step 1: Package the application into .intunewin format

Start-Process -FilePath $IntuneWinToolPath -ArgumentList @("-c", $SourceFolder, "-s", $SetupFile, "-o", $OutputFolder, "-q") -Wait -WindowStyle Hidden
Write-Host "Intunewin file created under $OutputFolder"

Step 2: Authenticate with Microsoft Graph API

$TenantId = "YourTenantID"
$ClientId = "YourClientID"
$ClientSecret = "YourClientSecret"

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

$TokenResponse = Invoke-RestMethod -Uri "https://login.microsoftonline.com/$TenantId/oauth2/v2.0/token" -Method Post -Body $Body
$AccessToken = $TokenResponse.access_token

Step 3: Upload the .intunewin file to Intune

$IntuneWinFilePath = Join-Path -Path $OutputFolder -ChildPath "$SetfileName.intunewin"
$FileContent = [System.IO.File]::ReadAllBytes($IntuneWinFilePath)
$EncodedContent = [Convert]::ToBase64String($FileContent)

$Headers = @{
    "Authorization" = "Bearer $AccessToken"
    "Content-Type"  = "application/json"
}

$AppMetadata = @{
    displayName = $AppName
    description = "Description of your app"
    publisher   = "Your Publisher"
    isFeatured  = $false
    informationUrl = "https://yourappwebsite.com"
    privacyInformationUrl = "https://yourappwebsite.com/privacy"
    installCommandLine = "msiexec /i $SetupFile /qn"
    uninstallCommandLine = "msiexec /x $SetupFile /qn"
}

$MetadataResponse = Invoke-RestMethod -Uri "https://graph.microsoft.com/v1.0/deviceAppManagement/mobileApps" -Method Post -Headers $Headers -Body ($AppMetadata | ConvertTo-Json -Depth 10)

Write-Host "Application uploaded successfully!"

Step 4: Upload Icon

$IconContent = [System.IO.File]::ReadAllBytes($IconPath)
$EncodedIcon = [Convert]::ToBase64String($IconContent)

$IconMetadata = @{
    icon = $EncodedIcon
}

Invoke-RestMethod -Uri "https://graph.microsoft.com/v1.0/deviceAppManagement/mobileApps/$($MetadataResponse.id)/icon" -Method Patch -Headers $Headers -Body ($IconMetadata | ConvertTo-Json -Depth 10)

Write-Host "Icon uploaded successfully!"

Step 5: Configure Detection Method

$DetectionChoice = Read-Host "Enter choice"

if ($DetectionChoice -eq "1") {
    $DetectionRule = @{
        detectionType = "file"
        path = "C:\Program Files\$AppName"
        fileOrFolderName = "$AppName.exe"
    }
} elseif ($DetectionChoice -eq "2") {
    $DetectionRule = @{
        detectionType = "registry"
        keyPath = "HKLM\SOFTWARE\$AppName"
        valueName = "Version"
    }
} elseif ($DetectionChoice -eq "3") {
    Write-Host "Using custom detection script..."
    $ScriptContent = [System.IO.File]::ReadAllBytes($DetectionScriptPath)
    $EncodedScript = [Convert]::ToBase64String($ScriptContent)

    $DetectionRule = @{
        detectionType = "script"
        scriptContent = $EncodedScript
    }
} else {
    Write-Host "Invalid choice. Defaulting to file detection."
    $DetectionRule = @{
        detectionType = "file"
        path = "C:\Program Files\$AppName"
        fileOrFolderName = "$AppName.exe"
    }
}

Invoke-RestMethod -Uri "https://graph.microsoft.com/v1.0/deviceAppManagement/mobileApps/$($MetadataResponse.id)/detectionRules" -Method Post -Headers $Headers -Body ($DetectionRule | ConvertTo-Json -Depth 10)

Write-Host "Detection method configured successfully!"

Can someone help to get it fixed, I have already created the App registration with appropriate permissions. Thanks you!

Error: Bad request 404 at the Invoke-request command line. Unautorized access.