Re-trust the Employee Training Management for Office 365 Add-in

In case you have to re-trust the Add-in, please follow this guide.

Go to site Contents, click on the add-in’s context menu and click on ‘Permissions’ in classic mode or ‘Manage permissions’ if you use the modern design.

Classic mode:
Manage permissions classic mode

Modern design:
Manage permissions modern design

Now click on ‘here’ to re-trust the Add-in.
Re-trust the add-in