I've a REST API, with an OAuth 2 authentication mechanism (FOSOAuthServerBundle on a Symfony 3 application).
To get/refresh a token, the URL look like : https://api.example.com/oauth/v2/token?grant_type=[password|refresh_token]&client_id=[client_id]&client_secret=[client_secret]&username=[username]&password=[password]
This works great on server-to-server calls, but can't be applied on Javascript apps.
How can implement API Oauth 2 authentication from a front application ? (JWT is not present on the server).