title: how to include/get "target contact" in xero "invoices" post/get api calls.
body: <p>I am new to xero and currently doing POC, by using these services -><a href="https://app.xero.com/Preview/invoices/get" rel="nofollow noreferrer">GET call</a>
  Can I get/add target contact to invoice using given service as images which are uploded. I referred <a href="https://developer.xero.com/documentation/api/invoices" rel="nofollow noreferrer">API docmentaion</a>. But no luck. Can you please help me out.</p>
  
  <p><a href="https://i.stack.imgur.com/0q0gy.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0q0gy.jpg" alt="Add customer by UI"></a></p>