How to list open PR for a branch using API

Question

i was trying to get the list of open pull request for a branch. i tried hitting this API

GET /2.0/repositories/{username}/{repository_slug}/pullrequests?state=OPEN&source.branch.name={branch_name}

i got this response: 
{"type": "error", "error": {"message": "Your credentials lack one or more required privilege scopes.", "detail": {"required": ["pullrequest"], "granted": ["repository:delete", "repository:admin", "repository:write"]}}}

sidhant · Answer

yeah but I already have admin access for this but still it is not inheriting all the write access

Aron Gombas _Midori_ · Answer

The message means that whatever authentication you used, it is not permitted to work with pull requests.

"required": ["pullrequest"]

...means that you need the "pullrequest" scope to make this REST API call.