What is the best is the best OAuth grant to use in developing a front-end only app

I am very new to OAuth and I intend implementing an api for a frontend only (html and JavaScript) web app with login abilities using laravel Passport. Both the frontend app and the API server will reside on different servers. I have read a lot about different grants but still confused about which will be best suited for what I intend doing. Are the access tokens going to be stored on the front end (using local storage or cookies)? I am just confused about where to even start from.

via Chebli Mohamed