title: How to fix "Invalid mapping expression parameter specified" in Amazon API Gateway
body: <p>As you can see, I tried to set a simple query param called 'name'.</p>
  <p>TBH, I don't fully understand what does &quot;Mapped from&quot; mean, <a href="https://docs.amazonaws.cn/en_us/apigateway/latest/developerguide/api-gateway-create-api-step-by-step.html#api-gateway-create-resource-and-methods" rel="nofollow noreferrer">I just followed the official example document here (step 7)</a> and set it to <code>method.request.querystring.name</code>. However it is still complaining that it is not valid.
  <a href="https://i.stack.imgur.com/eBu6s.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eBu6s.png" alt="enter image description here" /></a></p>