Thanks for helping, but I've decided to give up on Let's Encrypt. It's just not worth the hassle.
The first time I installed a Let's Encrypt certificate, I couldn't do it through cPanel; I needed a request to an admin to manually install it.
Some time later, the certificate stopped working. I had to go into cPanel and re-install the certificate in my site.
I couldn't renew the certificate through cPanel, apparently due to some undisclosed issue with my .htaccess file.
The certificate worked when you installed it. However, it was installed on all my domains, instead of just on my test domain, bbmap.tk. I didn't want it on my main domain, and couldn't figure out how to only have it apply to my test domain, so I've deleted the certificate and will operate without it.