Action bar with back arrow
<p>I am making an app and I want to put an action bar with a back arrow in a fragment.<br>
So, I already have the fragment with the action bar but don't know how to put the back arrow on it. 
Can you help me please?<br>
Thank you,<br>
Guilherme<br>
<a href="https://i.stack.imgur.com/NJKwD.jpg" rel="nofollow noreferrer">This is the fragment with an action bar tag</a></p>