<app name> needs permission to access resources in your organization that only an admin can grant. Please ask an admin to grant permission to this app before you can use it.
This error occures when an Azure Active Directory administrator needs to approve (or what Microsoft calls consent) the application in Azure Active Directory so he approves that this application can use Azure Active Directory.
- Log on to the Azure Portal
- Open Azure Active Directory
- Open App Registrations
- OPen your Application
- Click on Required Permissions
- Click on Grant Permissions
You can find more info here: https://www.youtube.com/watch?v=g6d1z8Wu7SA