Implicit flow not working?

Hello,

I’m trying to develop an React Native app integrated with my own WP site using your WP OAuth Server plugin.

authorize request with response_type=code works fine, but request with response_type=token returns following error.

unauthorized_client
The grant type is unauthorized for this client_id

I’m confirmed that both ‘Authorization code’ and ‘Implicit’ are checked in client settings and advanced configurations.

Thanks