userAttributes
An array of name-value pairs representing user attributes.
For custom attributes, you must add a custom:
prefix to the attribute name.
If you have set an attribute to require verification before Amazon Cognito updates its value, this request doesn’t immediately update the value of that attribute. After your user receives and responds to a verification message to verify the new value, Amazon Cognito updates the attribute value. Your user can sign in and receive messages with the original attribute value until they verify the new value.