identityValidationExpression

A validation expression for the incoming identity token. For TOKEN authorizers, this value is a regular expression. For COGNITO_USER_POOLS authorizers, API Gateway will match the aud field of the incoming token from the client against the specified regular expression. It will invoke the authorizer's Lambda function when there is a match. Otherwise, it will return a 401 Unauthorized response without calling the Lambda function. The validation expression does not apply to the REQUEST authorizer.