Stripe Customer->sources->create error

I have stripe integrated in a project. when i try to pay it just gives me an error "Call to a member function create() on null" on line 414 and this is the line "$card = $customer->sources->create(['source' => $token]);" now i saw the code and on searching it turns out stripe does not return sources with customer after latest update. they say you have to put "expand" when sending a request, now i dont know how it works in vendor files and dont wanna mess with anything. so if someone could provide a proper fix ? laravel => 6.0 cashier =>9.0