Servlet call rejected with CSRF token issue

Hello-

Need some advice on the best possible approach to make a servlet POST call from a servlet browser.

Our Objective : From Appian user servlet browser, upload large files using graph API to sharepoint using chunking. This solution works perfectly fine on standalone eclipse but getting hiccups on Appian cloud.

We cannot do this using traditional route as sharepoint API has a limitation of 250MB, our files are 1gb & beyond.

couple of approaches i tried :

1. Moved all the logic directly into the browser, including the session creation...but Azure rejected this approach not allowing to create session from the browser...
2. 2nd approach Appian UI to HTML interface making a Servlet POST call to initiate a upload graph api session & return the token back to HTML & from here making all the grinding to sharepoint, here we are getting CSRF token rejection