Vscode live server extension

I have a project based on Codeigniter 3 and coded using Vscode. I'm using a local server via Wamp which appears to be running perfectly and the Wamp virtual host page links to various websites, all displaying properly. I want to use the Live Server extension which I have installed in Vscode along with another extension called PHP Server. I have installed the Chrome Live Server Web Extension in my browser, correctly configured and switched on. What I am now supposed to do (from a number of Youtube videos) is click the Go Live button in Vscode, open the root index.php file, right-click it and choose to reload the server. That does indeed open the project website but unfortunately does not refresh the page which is the whole point of Live Server. I have looked at all  the Live Server settings but I can't find anything relevant. Can anyone enlighten me about what is going wrong? Is it perhaps a Codeigniter thing?

Live server works only with html pages.

If plan A fails, relax... the alphabet is 26 letters

Well I have watched about a dozen Youtube videos assuring me that it should work with php - but perhaps that is with a simple structure, not with a framework like Codeigniter. What I have done as a workaround is to remap the F11 key as a refresher instead of Ctrl+F5.