You are using an old API version (2022-04). Consider upgrading to a newer one, like 2023-10 to avoid runing into any stability issues.
Is the ShopName variable in the URL containing a valid shop name? The red background indicates that Postman does not have a value there as far as I can see. Try either adding the variable value or by replacing it with your shop name for testing.
Could you share which GraphQL query or mutation you are trying to send? It would be helpful to debug the issue further.
I was able to reproduce the issue with the parameters you provided, by modifying the path after {{ShopName}}.myshopify.com to an invalid string.
For example, an extra whitespace after graphql.json got me the authentication page reply as well. As soon as I removed it, the API responded nominally.
Can you check if the path in Postman is indeed correct and does not contain hidden characters? Try by replacing it with this path which I just validated:
I have tried with the link given above but still not working. I have also checked on all possible place that invalid character can be appear and no invalid character being found.
Finally resolved the problem. The issue occur since I have set the authorization as basic auth. It will require Inherit auth from parent type for graphql