title: how to use getSupportFragmentManager() in Activity
body: <p>When I change </p>
  
  <pre><code>public class Bmr extends Activity implements View.OnClickListener {
  </code></pre>
  
  <p>to</p>
  
  <pre><code>public class Bmr extends appcompatactivity implements View.OnClickListener {
  </code></pre>
  
  <p>this <code>getSupportFragmentManager()</code> is working  but I need to work with <code>Activity</code> class. Are there any options how to do it?</p>