Hi @narayanan,
if you’re using OAuth to sign in in the WebPortal (a button that forwards you to another sign-in page), then these accounts will not work for REST directly. The server administrator would need to add/configure a realm for user/password based authentication, though that is probably a bit out of scope here.
Instead, you can try using JWT tokens. You can manually create one by calling the /rest/v4/auth/jwt endpoint when logged in to the WebPortal (e.g. via our REST documentation on Swagger: <your-server>/knime/rest/doc/index.html#/Session/getJwt_1):
You can then use the token in the authorization header, as shown in How to use get request node using bearer token - #2 by bruno29a and you can set the Authentication tab to “None”. By default, these tokens can’t be valid for longer than 30 days, but you can use a valid token to call the endpoint and get a new token.
Kind regards
Marvin