Have set up SSL but just get "ERR_SSL_PROTOCOL_ERROR"

[KangJL]

This is expected of self-signed cert.
You should get SSL cert from Let’s Encrypt

How to get Free SSL (HTTPS) on InfinityFree

If you’re using free hosting with your own domain or a subdomain, you’ll want to make your website work over HTTPS (SSL). Fortunately, InfinityFree provides all the tools you need to make it so. If you like videos better then text guides, scroll on down to the bottom of this guide. This guide uses the control panel functions and the Free SSL Certificates tool provided by InfinityFree to get SSL up and running on your site. Step 1: Set up the domain on your hosting account The first thing to do…