import offlineStorage from 'core/js/offlineStorage';

offlineStorage.set('status', 'completed');

or

Adapt.offlineStorage.set('status', 'completed');

https://github.com/adaptlearning/adapt-contrib-core/blob/69044466207afba515edf28c6f5e0a2eac566cbc/js/offlineStorage.js#L68

https://github.com/adaptlearning/adapt-contrib-spoor/blob/5caf519a05347b6c7c63f77a97c977786e1a5436/js/adapt-offlineStorage-scorm.js#L144-L145