Authenticate Power BI Web App without displaying GUI authentication

[sparksy64]

I have created a web application that authenticates a users right to view a report using a simple form based authentication that is separate from azure ad.

Is it possible to embed a report into an iFrame without displaying the GUI authenticate from Azure, as they will not have accounts that can access this. I don't want to make the reports public either.

This question has already been asked however, the methods used to solve are not ideal and are now outdated and so cannot be applied anymore with new packages.

Any help would be appreciated, thank you.