title: Azure Application gateway cannot upload pfx certificate
body: <p>For Application gateway all documentation says to upload pfx certificate but when I go to http settings for backend pool it only allows ".cer" certificate and it wont allow ".pfx" file to be uploaded, error displayed says wrong format ? 
  m i doing something wrong or somehow Azure has changed functionality but documentation is still not uploaded . 
  Strangely through this command I am able to upload PFX</p>
  
  <pre><code>az network application-gateway ssl-cert create
  </code></pre>
  
  <p>Screenshot attached</p>
  
  <p><a href="https://i.stack.imgur.com/OJUen.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OJUen.png" alt="enter image description here"></a></p>
  
  <p>Update : I am trying to do this for an existing Application Gateway
  Update 2 : Strangely when I am creating a gateway Azure shows me option for PFX but I dont know why it become cer if I am trying to do this for an existing one.</p>
  
  <p>Is this one of Microsoft's easter eggs??</p>