title: Why is the Approve button disabled in GitHub "pull request review"?
body: <p><strong>Problem Background:</strong></p>
  
  <p>So far I am the sole owner of a GitHub repo. I committed the code from my system to a branch called release (actually its a tag based on develop branch, if that matters). In GitHub, I created a pull request where <strong>base branch is master</strong> and <strong>compare branch is release.</strong> </p>
  
  <p>But I am only <strong>allowed to comment on review, not allowed to approve</strong>. What may be the reason? </p>
  
  <p><strong>Note:</strong> There is no merge conflicts and while creating the pull request the green signal of merging possible was displayed.</p>
  
  <p><a href="https://i.stack.imgur.com/c3Ix5.png" rel="noreferrer"><img src="https://i.stack.imgur.com/c3Ix5.png" alt="enter image description here"></a></p>
  
  <p><strong><em>Here is how the master branch is protected by me:</em></strong></p>
  
  <p><a href="https://i.stack.imgur.com/VFbgo.png" rel="noreferrer"><img src="https://i.stack.imgur.com/VFbgo.png" alt="enter image description here"></a></p>