Saylor Academy have the following suggestion for Moodle
The plugin currently makes an API call to Accredible to issue a certificate when a trigger event occurs (for us, exam completion).
Sometimes, an API call will fail but there's no retry mechanism the way the plugin is currently architected.
If instead of firing off the API call when the trigger event occurs, the event instead creates an ad-hoc background task that fires off the call, Moodle should automatically keep retrying when the call fails.