Authenticate with Custom JWT Token issue

Dear all,

I am working on a Flutter Web app and authenticate users with Microsoft Entra ID which I get a JWT session token from. I would like to authenticate Atlas App Services with this JWT token as well.
The setting is set so any organisation can log in, the openid configuration link is given as follows:
Here I get the JWKS URI

When I try to authenticate users with: , I get the following error:
crypto/rsa: verification error

I would appreciate it greatly if anyone could help me with this.

Best regards,