A free SSL certificate can be created at any time for your existing domains in the customer portal at https://portal.ip-projects.de.
In the customer portal, select SSL in the side navigation:
Then, all you have to do here is specify the domain for which you want to issue the SSL certificate. Please note, however, that the free SSL certificate can only be issued for existing domains. You can find out which domains you own under the side menu item Domains / DNS. Finally, all you have to do is click on create.
Note that you save the private key via the save icon on your computer. This is especially important, as you will not be able to download it later:
Finally, the certificate is created and can be downloaded: