title: Assigned scope permission is not recognized in Slack API request
body: <p>I am facing the same issue as this question</p>
  <p><a href="https://stackoverflow.com/questions/50235774/slack-api-opening-a-new-dm-scopes-and-permissions">Slack API Opening a New DM (Scopes and Permissions)</a></p>
  <p>I have these permissions assigned
  <a href="https://i.stack.imgur.com/oQCWK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oQCWK.png" alt="enter image description here" /></a></p>
  <pre><code>   ok error         needed   provided
     -- -----         ------   --------
   False missing_scope im:write identify,channels:read,users:read
  </code></pre>
  <p>The self-answer in the other question implies that I need to use the bot token, instead. I don't think I have a bot token (and am not the application administrator so I can't get in), but it seems like I should be able to submit this with the user token as well.</p>