LMS help

I built a module for a freelance client who needs a cheaper LMS.

He needs a certificate made for them and completion tracked.

The users would be taking the course once and then probably wouldn’t need to login again. So you could say they wouldn’t be active users, they would be high school students taking a module through their school.

Any recommendations?

Edit- I fogot to mention, he estimated that up to 500 users could be doing the course a year.

I know moodle is typically used with schools, would this be doable? It seems cheaper.