switch for RSA when generating SSL-certificate

[thunermay]

Is your feature request related to a problem? Please describe.
My problem is that I have a webserver (from my router) that only accepts certificates/privates keys that are generated via RSA. It also contains a self-generated certificate. I was hoping to fully ignore the webservers certificate because I have the proxy manager, but whatever I try to change at the config, the proxy manager forwards the certificate from my router.

Describe the solution you'd like
It would resolve the issue if you could discard the certificate of the underlying host. Also it would be great to have the option to go back to RSA. I tried to change the letsencrypt.ini file without success.

Describe alternatives you've considered
An alternative would be to create the certificate manually and upload it but that isn't practical because they expire every 90 days.

Additional context

[tom-xy]

This is a nice feature that provide a custom letsencrypt.ini file configuration option. I need to use certificates with RSA keys. Thanks.

[github-actions]

Issue is now considered stale. If you want to keep it open, please comment 👍

[iyinchao]

This is really handy feature as some of my services require RSA type SSL key. Hope this feature be added soon 👍 #4218