title: Trying to setup user pool authentication for API Gateway
body: <p>I'm trying to setup security on an API using Cognito user pools. I'm getting back 401 Unauthorized.</p>
  
  <p>The API and User Pools are existing, and I've been using the user pool to log into an application. I'm now trying to secure the API calls.</p>
  
  <p>I created an authorizer on the API,</p>
  
  <p><a href="https://i.stack.imgur.com/W3QU2.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/W3QU2.jpg" alt="Authorizer"></a></p>
  
  <p>Then I added the authorizer to one GET method in the API</p>
  
  <p><a href="https://i.stack.imgur.com/m3rmV.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/m3rmV.jpg" alt="enter image description here"></a></p>
  
  <p>Then finally I tried to test the API in Postman. I'm using the AWS Signature authorization.</p>
  
  <p><a href="https://i.stack.imgur.com/AudPt.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AudPt.jpg" alt="enter image description here"></a></p>
  
  <p>Calling the method returns 401. The method functioned before with no security, and turning off the authorizer makes it work again (without security).</p>
  
  <p>Any ideas what step I'm missing?</p>