Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
If you can't use sudo and you can't login to a root shell on the server but you also don't have a control panel to manage your site, how do you manage your site, exactly?
Note that it can be possible that Ionos doesn't offer the possibility to install free certificates like certs from Let's Encrypt.
There is a control panel, but I used rsync and ssh to populate the website from my copy of it on my mac mini. How would I use the control panel to install certbot?
Uhh, sorry to be dense, but how would I "directly request the certificate and enable SSL."? I've been around Unix/Linux a few decades now but I've never figured out how certs work. Trying...
It's about your ISP. You have to find out what their procedure is supposed to be. There could even be a switch in your panel, that you can click once and enable SSL. Or you'd have to give them a certificate to install... and that's also doable, but in that case you should look for a different ISP. Or even worse, they could try and sell you a certificate.
@jimmyakers1949, enabling a certificate on a web site is an administrative function (it requires reconfiguring the web server application, e.g. editing Apache or Nginx config files). Normally by default you would need sudo access to do that.
However, many control panels delegate this (and some other web server configuration edits) to a control panel UI feature. In that case, the control panel may allow you to request the relevant change even though you aren't the system administrator.
But the details of how this works are different from control panel to control panel, and may also not be enabled by the system administrator even if the control panel software did support it.
If you don't have a relevant UI option in the control panel, you can most likely not do this by yourself with your existing hosting plan. There is no more general way that a non-administrative user could import a certificate without an administrator's help. (Obtain, yes; import and use, no.)