We are using Azure devops with the workflow for each task as:

1. Task branch to Release branch
2. Then Release branch to master

The reviewer will approve each pull request.  

However, a user creating a PR can also create one from task branch directly to master.

[![enter image description here](https://i.stack.imgur.com/Z53WF.png)](https://i.stack.imgur.com/Z53WF.png)

Is there any way, by policies/validations that the system can prevent creation of the PR itself, which is from task to master.