Teams App - Multi Tenant Authentication

Hi,

I'm currently developing a Microsoft Teams App which gathers data from the Graph API and the SharePoint API.

To authenticate with Microsoft Graph I followed the tutorial here, this works like a charm.

I just added the graph endpoint to the Adal config and I receive my authentication token.

If I add a SharePoint tenant to this endpoints list I also receive a token that works to use the SharePoint API.

HOWEVER as I stated above, the apps should be multitenant so I can't just 'add' a tenant to the endpoint as in the image above. How do I handle this type of authentication to be multitenant?

Thanks in advance.