401 Unauthorized -- Invalid grant when requesting refresh token in Doorkeeper
<p>I'm having a trouble in requesting a refresh token, it keep returning an Unauthorized 401 error. I don't know if I'm lacking a parameters that I passed when I did a request.</p>

<p>I added the doorkeeper configuration for refresh token.</p>

<p><code>use_refresh_token</code></p>

<p>Here's the request details:</p>

<p><code>{{root_url}}/oauth/token</code></p>

<pre><code>{"refresh_token"=&gt;"034a74c085219fb8297fd8ef9b59f080918f"
 "format"=&gt;:json,
 "controller"=&gt;"/oauth/tokens",
 "action"=&gt;"create",
 "grant_type"=&gt;"refresh_token",
 "client_id"=&gt;"&lt;client_id&gt;",
 "client_secret"=&gt; "&lt;client_secret&gt;"}
</code></pre>

<p>Error descriptions:</p>

<pre><code>{:error=&gt;:invalid_grant,
 :error_description=&gt;
  "The provided authorization grant is invalid, expired, revoked, does not match the redirection URI used in the authorization request, or was issued to another client."}
</code></pre>

<p>Btw, all of my api request authentication is not failing just this refresh token. I wonder what I'm missing in the request parameters.</p>