Yeah, I found it! I could have sworn I looked there, but I was probably looking at the center section not the Admin block.
Now the issue is that only Manual Enrolment is showing as a method.
I went back to Site Admin/Advanced Features/Plugins/Enrolments/Manage Enrol Plugins. The External Database shows the open eye, the settings look correct, but when I test settings, I get an error:
Test enrol settings - External database
×External course table not specified.
(mysqli): SELECT * FROM wp_usermeta
×External enrolment table contains following columns:
umeta_id, user_id, meta_key, meta_value
wp_usermeta is the correct table that contains the fields I'm looking for, and that is what I put into Remote user enrolment table under Remote enrolment sync.
This is a MySQL database used by WordPress, with a table added by a plugin to restrict access.
I just set up the cron job to sync users from the database, I don't know if that'll make a difference.