title: How do you acces IdentityUser to change its role?
body: <p>I want to change the role of a user in my application.</p>
  
  <p>I used Dependency Injection to access  UserManager _usermanager in my controller. To change the role I'm supposed to call _usermanager.AddToRoleAsync(IdentityUser user, string role), but I can't seem to locate the a IdentityUser enity. </p>
  
  <pre><code>    [HttpPost]
      public async Task&lt;IActionResult&gt; BewerkGebruiker(int id , ... )
      {
          Gebruiker g;
          using (var context =  new UTILcontext())
          {
              _userManager.AddToRoleAsync(&lt;&lt;what do i put here?&gt;&gt;),Rol);
              _manager.UpdateGebruiker(g);
              return RedirectToAction("Gebruikers");
          };
  </code></pre>