Stripe and Cashier (help!)

$user = User::find(1);

$user->newSubscription('main', 'monthly')->create($creditCardToken);

This is what laravel tells me to use for creating a new subscription. But I'm not sure about how the flow works. When a person makes a payment, do i do a Route::post and just put this information in there, expecting laravel to take care of everything? I know that laravel will make changes to the database, but where is the validation happening (credit card going through validation)?