My website is hosted on a shared server 1 and 1
How to integrate let’s encrypt ? 1and1 offers for their own SSL certificates
I think 1and1 shared hosting does not support external SSL as explained in this post https://community.letsencrypt.org/t/1and1-response-to-query-to-allow-letsencrypt-certs/11273. But please let us know if you have any update on it.