title: Generate access token with IdentityServer4 without password
body: <p>I have created ASP.NET Core WebApi protected with IdentityServer4 using ROPC flow (using this example: <a href="https://github.com/robisim74/AngularSPAWebAPI" rel="noreferrer">https://github.com/robisim74/AngularSPAWebAPI</a>).</p>
  
  <p>How to manually generate access_token from the server without password?</p>