title: How do I setup an Endpoint URL with a Path Parameter within API Gateway?
body: <p>I'm trying to setup an API Gateway in front of my existing setup. Whenever I try to add an endpoint with a parameter, I get an error.</p>
  
  <pre><code>Invalid mapping expression specified: Validation Result: warnings : [], errors : [Invalid mapping expression parameter specified: method.request.querystring.type]
  </code></pre>
  
  <p>Here are screenshots:</p>
  
  <p><a href="https://i.stack.imgur.com/9FFFq.png" rel="noreferrer"><img src="https://i.stack.imgur.com/9FFFq.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/aN7I2.png" rel="noreferrer"><img src="https://i.stack.imgur.com/aN7I2.png" alt="enter image description here"></a></p>
  
  <p>What am I doing wrong?</p>