In the following, we will show how to create and store an SSL certificate from Let's Encrypt in Plesk.
First of all, we log in to our booked web hosting package - in our example this is https://web3.ipp-webspace.net:8443. Here we should then be able to view our existing domains. Here, before creating the Let's Encrypt certificate, we have to make sure that the domain points to the webhosting IP via A-record (IPv4) and AAAA-record (IPv6) and is resolvable. Then we click on SSL/TLS certificates.
Now we can edit or remove already existing SSL certificates, or create new ones. In our case, we go to "Install free basic certificate from Let's Encrypt" and click on Install.
Afterwards, a window opens in which we can select what exactly we want to protect. In our case, we select everything once. Then click on Use for free to issue the certificate.
The certificate is then issued and stored at the same time.