Power Bi rest Api

Hi! 

So I'm developing a modern web app using flask + Angular, and my backend (flask) is stateless.

I need to call some APIs in the backend like get reports, dashboards of a user ... is there any solution to this ?

- I tried to register the backend app in azure portal as a web app but the problem is that the login will be requested from the front and the redirect uri is on the backend + the backend is stateless so it was impossible to implement.

- Then I tried to register the frontend as an spa but the problem is that I need to process the data received from the requests in my backend app. 

Any solution to this situation please ??

Thank you in advance