cPanel is notoriously bad for managing redirects. (I didn't think you could create HTTP to HTTPS redirects using cPanel alone?)

> I do not know if this is possible...

Probably not from cPanel. But this is relatively straightforward in `.htaccess` (by directly editing the file itself). To be honest, if something of this nature is not possible in `.htaccess` then it's probably not something you should be doing in the first place.

If you simply want to redirect from HTTP to HTTPS on the same _hostname_ then all you need is something like:

    RewriteEngine On

    # Redirect HTTP to HTTPS on the same host
    RewriteCond %{HTTPS} !=on
    RewriteRule .* https://%{HTTP_HOST}%{REQUEST_URI} [R=302,L]

The `HTTP_HOST` server variable contains the _hostname_ from the request. eg. `example1.com`, `example2.com`, `www.example1.com`. Note that this alone does not canonicalise the www subdomain.

This is also a 302 (temporary) redirect (the same as simply specifying the `R` flag by itself). Change to a 301 (permanent) only when you are sure it's working OK. (301s are cached hard by the browser so can make testing problematic.)

To canonicalise the www subdomain and redirect non-www to www then add an additional directive:

    RewriteEngine On

    # Redirect non-www to www (and HTTPS) on the same domain
    RewriteCond %{HTTP_HOST} !^www\.
    RewriteRule .* https://www.%{HTTP_HOST}%{REQUEST_URI} [R=302,L]

    # Redirect HTTP to HTTPS on the same host
    RewriteCond %{HTTPS} !=on
    RewriteRule .* https://%{HTTP_HOST}%{REQUEST_URI} [R=302,L]

This does assume that you don't have any other subdomains (other than www) on these domains.

No need to repeat `RewriteEngine` more than once.