that is only setting of what type of key you want to have, but i can see your domain is mostlikely missing a SSL certificate, make sure to generate one within cpanel, since cpanel offers 1. lets encrypt for free or 2.some other free SSL cert from cpanel themself.
Another suggestion is to flush mobile web browser cache and cookies, then try visiting your site again hopefully it get's https automaticly, if not go in dashboard from pc and set HTTPS to Forced. instead of automatic or manually.