How to check if the student already completed the course to show the button "finish course" and get the certificate?
I"d like to display the button only after the person finished 100% of the course and got minimum score on quiz.
This has already been implemented in the latest update of wplms.
If you use this tip:
https://wplms.io/support/knowledge-base/quiz-passing-score/ then the user cannot finish the course untill the user has passed the quiz.
The finish course button will be shown but the user cannot finish the course as it will give the error message to first finish all the units/quizes. There is also a setting in the course to force previous unit/quiz complete, if you enable this setting then user has to first finish the previous unit/quiz to go to the next unit.
Also refer this tip:
https://wplms.io/support/knowledge-base/quiz-passing-score/ to hide button.