Wix Headless: App installation error in website

Question:
When I’m trying to install my custom app to my wix site it gives me this error.

Product:
Wix Headless

What are you trying to achieve:
I’m trying to install app to my website from wix studio, it is showing me the error below, it says it couldn’t find redirect url, but I already have redirect url to the app oauth.

What have you already tried:
I was trying to generate auth_code to generate access token for oauth. For this purpose I have created auth_code by installing the app using url and app_id, app_secret after generating token. The installation process is done as per the documentation, and I have generated the auth_code, but in wix studio it is showing that the app is not installed with the website. So I was trying to install it again from wix studio, then I found out the error.

Additional information:
When I’m trying to use the auth_code I generated, using the postman response says it is invalid auth_code.

Hello! Sorry you are experiencing issues. The best place to report a bug with your app is through this link Contact Wix

If you think it might not be a bug and are looking for other app developers to chat with, the best place to find them is in Discord Wix Studio Community

Thanks for your response, can you please clarify my few confusions?

  1. I had generated auth_code 2days ago, and created auth_token using that code same day, but when I’m trying use the code to generate new auth_token it gives me error that invalid auth code. Is it required to generate code each time for generating auth token? but this is not possible to re-install the same app on the same website again and again to get the code.
  2. How to login using rest api from different website and access the collection data according to user logged in?