If you don’t have the private key, Revoke Old Certificate, then Reissue Certificate – on Firefox this is a bit weird but it’ll download the key file but until you open it won’t complete the reissue.
In Plesk go to Websites & Domains > SSL/TLS Certificates > Advanced Settings > Add SSL/TLS Certificate.
Enter a certificate name:
Scroll to “Upload the certificate files”:
Browse each file (it doesn’t matter that they’re cer rather than crt), use _INTERMEDIATE.cer for the CA certificate, then click Upload Certificate.
Remove the default Ubuntu install, otherwise you’ll get an error You don't have write permissions for the /var/lib/gems/3.x.x Directory and configure Ruby to install gems to a folder in your home.
