While adding a new domain to my WHM/cPanel installation, I received the following error:
The “cPanel (powered by Sectigo)” provider cannot currently accept incoming requests. The system will try again later.
After digging into this issue a bit, it looks like this had to do with a permissions issue.
To fix this, open Terminal and paste in the following:
find /var/cpanel/ssl/domain_tls/ -mindepth 1 -maxdepth 1 -name .pending_delete -prune -o -type d -not -perm 755 -exec chmod -v 755 {} \;
Then, run AutoSSL again and your certificate will finish installing.
Credit to Rex (cPanel user “cPRex“), a cPanel Staff Member.