Need Developer Help in Freshsales & Intercom OAuth Integration

We are developing an app for Freshsales and Intercom. To get the user details of the Intercom account I’m using Freshdesk Oauth. I have done with the code part but unfortunately, I did get a positive response from the Intercom side and I’m always getting an invalid state error.

When I implemented the same through my own API I was able to get user tokens from the Intercom side. There might be a chance I would have implemented it wrongly. I need some developer help from your side to achieve this.

Eagerly waiting for your reply to schedule a meeting with your developer.