How to use the @aws-cdk/aws-apigateway.AuthorizationType.COGNITO function in @aws-cdk/aws-apigateway

// ------------------------------------------------------------------------

    const api = new apigateway.RestApi(this, id + "API");
    const integration = new apigateway.LambdaIntegration(apiFunction, {
      // lambda proxy integration:
      // see https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html#api-gateway-create-api-as-simple-proxy
      proxy: true
    });

    // ------------------------------------------------------------------------
    // Cognito Authorizer
    // ------------------------------------------------------------------------

    const cfnAuthorizer = new apigateway.CfnAuthorizer(this, id, {
      name: "CognitoAuthorizer",
      type: AuthorizationType.COGNITO,

      identitySource: "method.request.header." + authorizationHeaderName,
      restApiId: api.restApiId,
      providerArns: [userPool.userPoolArn]
    });

    // ------------------------------------------------------------------------
    // Root (/) - no authorization required
    // ------------------------------------------------------------------------

    const rootResource = api.root;

    rootResource.addMethod("ANY", integration);

    // ------------------------------------------------------------------------
    // All Other Paths (/{proxy+}) - authorization required

const rootResource = api.root;

    rootResource.addMethod("ANY", integration);

    // ------------------------------------------------------------------------
    // All Other Paths (/{proxy+}) - authorization required
    // ------------------------------------------------------------------------

    // all other paths require the cognito authorizer (validates the JWT and passes it to the lambda)

    const proxyResource = rootResource.addResource("{proxy+}");

    const method = proxyResource.addMethod("ANY", integration, {

      authorizer: {authorizerId: cfnAuthorizer.ref},
      authorizationType: AuthorizationType.COGNITO,

    });

    // uncomment to use an access token instead of an id token

    // const cfnMethod = method.node.defaultChild as apigateway.CfnMethod;
    // cfnMethod.authorizationScopes = ["openid"];

    // ------------------------------------------------------------------------
    // Add CORS support to all
    // ------------------------------------------------------------------------

    Utils.addCorsOptions(proxyResource, corsOrigin);
    Utils.addCorsOptions(rootResource, corsOrigin);

    // ========================================================================