I have been trying to develop web pages locally (in Windows 10) and running in my local browser (chrome, vivaldi).  Right now I have 3 different ways to run simple servers locally:  php's built in server, python's http.server module, and vscode's LiveServer.  When I run the php server, I can execute php code properly, as one would expect.  But calling php urls using the other two, I get a "Save File" dialog!  Where is that coming from?   Instead of a simple "not found" I get the dialog.  So I have two questions:   (1) Why am I getting the save file dialog?  (2) Is it possible to process php files using LiveServer or python's http.server module (which I don't expect can ever support php)
if the save dialog is being shown it's cause the server can't interpret php code. You have to  check these servers configs to check their integration with PHP (if they they can do that).
Why do local test servers open a "save file" dialog?