title: How do I get access token from API
body: <p>Tech stack:
  Kotlin, Retrofit2</p>
  <p>What I want to do:
  I want to get access token from API</p>
  <p>My method to get access token is</p>
  <pre><code>https://demo2.gopos.pl/oauth/token?password={password}&amp;grant_type=password&amp;client
  _secret={client_secret}&amp;client_id={client_id}&amp;username={login}
  </code></pre>
  <p>I already have password, client secret, client id and login. The question is, how do I wrap it as Retrofit POST method so I could receive access token? Or maybe there is better way than using retrofit?</p>