title: Drupal8 Oaut2 add a grant type "password" to client
body: <p>I work on <strong>Drupal8</strong> project and created <strong>Rest API</strong>, everything works fine until I want to add <strong>Oauth2</strong> when I try to get a token I got an invalid grant type error.</p>
  
  <p>This is the error code:</p>
  
  <pre><code>{
      "error": "invalid_grant",
      "message": "The provided authorization grant (e.g., authorization code, resource owner credentials) or refresh token is invalid, expired, revoked, does not match the redirection URI used in the authorization request, or was issued to another client.",
      "hint": "Check the configuration to see if the grant is enabled."
  }
  </code></pre>
  
  <p>This is the url that i called:</p>
  
  <p><a href="http://myserver/oauth/token?grant_type=password&amp;client_id=6db9da8d-b831-4381-b279-381bc5a57e90&amp;scope&amp;username=webmasterrest&amp;password=webmasterrest&amp;client_secret=" rel="nofollow noreferrer">http://myserver/oauth/token?grant_type=password&amp;client_id=6db9da8d-b831-4381-b279-381bc5a57e90&amp;scope&amp;username=webmasterrest&amp;password=webmasterrest&amp;client_secret=</a>$S$EamACyfemGWic74kmkwUvphMmr9FL132KC297mI1GEkTKhyBJyAo</p>
  
  <p>I added a client, but I can't add a grant type "password" to this client, any help please? </p>