title: how can i change image for "fb:login-button" when doing facebook login
body: <p>i have implement facebook OAuth for my application.</p>
  
  <p>I want to change the standard image provided for facebook login and want to put my custom.</p>
  
  <p></p>
  
  <p><img src="https://i.stack.imgur.com/R0sNv.png" alt="enter image description here"></p>
  
  <p>Is there a way to do?</p>
  
  <p>How can i do it?</p>