For guidance, please see these 3 posts linked below, in which I have installed PHP to serve my file gain.php which I located in folder /usr/share/dump1090-fa/html/. This method did not disturb SkyView.
Any file (.php or .html) located in folder /usr/share/dump1090-fa/html can be served in a browser without disturbing Piaware SkyView. If the file name is myFile.php, the url will be
IP-of-Pi/dump1090-fa/myFile.php
File gain.php served stand alone
