SignIn() method for SSO end up with 400 bad request

[tharindubuddhi]

I have followed the example in Readme. My react app is running locally in
http://localhost:5173
and I have a login page
http://localhost:5173/login

My redirect URI default set in workos portal - http://localhost:5173
Also I changed it to http://localhost:5173/login

Both case end up having the following
Network request

https://api.workos.com/user_management/authenticate
PayLoad
{
"client_id": "client_XXXXXXX",
"grant_type": "refresh_token",
"refresh_token": null
}
Response
400 Bad Request
{
"error": "invalid_request",
"error_description": "Missing refresh token."
}

[outofgamut]

I'm dealing with something similar. Locally, the example react QuickStart works fine. Whenever I deploy it, the initial sign-in works fine. However, when I refresh the session state isn't retained. I'm getting the same 400 - missing refresh token error mentioned here. I'm assuming the AuthKit Provider handles that for me, but maybe I have to configure something explicitly in onRefresh?