Embedded dashboard get metadata fails with errors on console

I have been following .Net Core example from here.

When opening example I get similar errors then in: this ticket

The call to GET https://wabi-north-europe-redirect.analysis.windows.net/metadata/embed/dashboard/9b3585b9-91bc-4cf8-9aa8-b7592ee4cb27 is using;

Bearer "Embed view token" generated by GenerateTokenInGroupAsync call

Tested with external REST client;

GET https://wabi-north-europe-redirect.analysis.windows.net/metadata/embed/dashboard/9b3585b9-91bc-4cf8-9aa8-b7592ee4cb27

by using Bearer "Embed view token" -> I get 403

However, if is use external REST client;

GET https://wabi-north-europe-redirect.analysis.windows.net/metadata/embed/dashboard/9b3585b9-91bc-4cf8-9aa8-b7592ee4cb27

by using Bearer "Access token" -> It's 200 OK

How can I change the AJAX call (?) to use Access token, instead of Embed token.

Modified code sample added (azure app settings removed).

https://www.dropbox.com/s/743hxrbmwibdzr9/NetCoreSample.zip?dl=0