How to approve/deny an access request through the Okta IGA API?

I have been following the Okta IGA API documentation and found out that there are NO APIs/endpoints for Approving/Denying an Access Request.
I noticed that it is done by using a PATCH /api/v1/requests endpoint in the UI, so I was wondering what is the server-side REST endpoint for doing this. Is there a different mechanism that works here?

I appreciate your help here, thanks!