I'm trying to get a new accessToken and idToken by hitting the endpoint oauth2/token.

I got the refresh token from cognitoUser.authenticateUser() method in amazon-cognito-identity-js

Here's my sample request in postman:

URL (seems fine)

BODY (seems fine)

HEADERS (not sure)

Authorization: Basic Base64(client_id) - i used btoa() function in JS

Note: The pool does not have a client secret

Problem: When I test this out, this is the response

I believe I supplied the right data as documented here: https://docs.aws.amazon.com/cognito/latest/developerguide/token-endpoint.html

grant_type: refresh_token
client_id: required if does not have a secret
refresh_token: refresh token here

Is there something that I'm missing or something I did wrong? I am not very familiar with the flow. Any help is greatly appreciated!