Using PR merge API endpoint with repository access token does not work

Issue Summary

When merging a pull request via API endpoint, it does not work using a repository access token as the authentication method.

Steps to Reproduce

1. Create a repository access token in a repository
2. Merge an open pull request using the API endpoint below and run it in a CURL command

   curl -vv --request POST \
     --url 'https://api.bitbucket.org/2.0/repositories/workspace_id/repo_name/pullrequests/pull_request_id/merge' \
     --header 'Authorization: Bearer ACCESS_TOKEN_HERE' \
     --header 'Accept: application/json' \
     --header 'Content-Type: application/json' \
     --data '{
     "message": "merge",
     "close_source_branch": false,
     "merge_strategy": "merge_commit"
   }'
   

Expected Results

The pull request will be merged using a repository access token

Actual Results

The pull request can't be merged using a repository access token

Workaround

A possible workaround is to use a Bitbucket Cloud username and app password for authentication or use OAuth 2.0 to generate an access token.