My web server is not a standard Apache server, so the certbot software won’t work. However the SSL certs used are Apache format. And I can generate a CSR from my server. That’s what I do when purchasing SSL certs from GoDaddy.
I know I need to manually redo this every so often with Let’s Encrypt until I figure out how to automate it. But in the meantime, is there some way I can manually submit my SSL request and get a cert in return? I can authenticate with files uploaded to my server as needed.