Rest API 'Get one supplier registration request' return 401

Summary:

I am trying to use the rest API 'Get one supplier registration request' but it returns 401 Unauthorized while other API in the same document can return right value.

Here is the document link:

https://docs.oracle.com/en/cloud/saas/procurement/23d/fapra/api-supplier-registration-requests.html

Please help about this issue.

Version (include the version you are using, if applicable):

23D