MaheshKumarSharma have a look at Laravel Passport which provides oauth authentication for your Laravel app and Flagrow Passport which enables Flarum to be an oauth client for it.
If you want a deeper integration with single sign on or shared database you will have to get your hands dirty because it hasn't been done yet
Also this question has been asked many times and a quick search for "laravel" here would have given you those answers already 🙄
