AuthorizationError.USER_PERMISSION_DENIED or invalid_grant

[fp.mm...@gmail.com]

I'm trying to do my first AdWords API call and I get an error:

AuthorizationError.USER_PERMISSION_DENIED

This is my credentials:

1. Developer token - Production token from my MCC

2. Client customer Id - The test AdWords account ID under test MCC account

3. Client id - My id from google api console
4. Client secret - My secret from google api console
5. Refresh token - token which I get under Production MCC account

Why I get this error? I read about this on a forum and I understand - There is no link between the manager account authenticated in the request and the client account specified in the headers.

When I try to change Refresh token which I get under Test MCC account I get new error:

error: 'invalid_grant', error_description: 'Bad Request'

So, guys, how do you do the correct request?