offsite payment page redirection issue

[babaraliamwal]

I have created an payment app and an app extension classified as an "Amwal Pay." I successfully installed the app, and my payment method is now appearing at checkout.
However, I am experiencing an issue with redirecting to my offsite payment page. When I attempt to place an order through my payment app, it does not redirect to the offsite payment page and instead returns an error (please see the attached screenshot for clarification). I have ensured that the payment_session_url in my payment extension is set correctly.

Could you please help me resolve this issue?