How to get authorization result with user assertion when second visiting?

[ClareMu]

Hi,
In the sample code, graph API needed authorization is got from Authorization cached when logging into AAD, but AAD will cache the user logging info, which means when I visit the restAPI in the second time, I don't need to log in again, so I won't have Authorization cached, authContext.AcquireTokenSilent(graphResourceId, credential, new UserIdentifier(userObjectID, UserIdentifierType.UniqueId));
these code can not read the property authorization.

My question is, is there another way to read authorization with user assertion from context when user visit the API in second time?