The best way to check if your users are having an active subscription and activate the premium features accordingly is to keep a copy of their current subscription state on your database.
To do that you will need to configure webhooks that will be called when a subscription is created or updated on Stripe.
Those are required to support shared subscriptions and subscription transfers
The subscription webhook
To store the updated state of your customer's subscriptions
To handle new user already having a subscription, either because they were added to a shared subscription or because you added their subscription manually from the Stripe Dashboard
