Can't put backend url in deauthorizing url

My backend domain is (https://example1.com) and frontend url (https://example2.com)
When I am putting frontend url to validate the domain address it is mismatch from the backend domain. and I am putting backend url in deauthorization url.

The domain is different (deauthorizing url and Validate the domain domain address) that is why it coming.
Please provide the solution.

Hello @akhilesh.chaurasiya0 please refer to this post please

Regards, Kwaku