WebView download in .NET MAUI

Hi everyone, I'm Manuel. I need to create an application which downloads a file from web site. I used a WebViewer and allowed into AndroidManifest.xml external memory read and write. Everything works fine until I press the download button from the website: nothing happens. I simply defined a webview into my MainApp.xaml.cs file (because it must be dynamic) and added into my GridLayout. I tried to print external memory read/write permissions, but it says it's not allowed.

Can anyone help me? I'm locked here from weeks and don't know how to solve.

Thank you so much