title: Infusionsoft API Opportunities customFields
body: <p>I have a tab called Buyer's Wish List in opportunity.</p>
  
  <p>I have leads created via API</p>
  
  <pre><code>$opportunity = array(
  'OpportunityTitle' =&gt; $full_name,
  'ContactID' =&gt; $newCon
  );
  $app-&gt;dsAdd("Lead", $opportunity);
  </code></pre>
  
  <p>Now how do I update custom fields in Buyer's Wish List tab under opportunity via API?</p>