Thanks @bmoren and @matthewjohnjamieson. I’ve copied the video and web examples, then a few of my own. It’s all good stuff.
One issue I have, is that the sketch examples refer to the host as localhost or 127.0.0.1 which is all good while everything is on one PC. Now I have server on RPi and web-page on PC or phone I put the server’s current IP address in the code. Is there a way for the web-page to get the server’s IP address?