stripeSubscriptionId is not being populated

stripe({
            stripeClient,
            stripeWebhookSecret: env.STRIPE_WEBHOOK_SECRET!,
            subscription: {
                enabled: true,
                onSubscriptionComplete: async ({ event, subscription, stripeSubscription, plan }) => {
                    console.log("event", event);
                    console.log("subscription", subscription);
                    console.log("stripeSubscription", stripeSubscription);
                    console.log("plan", plan);
                },
                plans: async () => {
                    const { plans, prices } = await getProducts();
                    return plans.map((plan, index) => ({
                        name: plan?.name!,
                        priceId: prices[index]?.id!,
                    }));
                },
            }

const completeSubscription = async () => {
        if (!selectedPlan) throw new Error("User doesnt have selected a plan");

        const { error } = await client.subscription.upgrade({
            plan: selectedPlan,
            successUrl: "/dashboard",
            cancelUrl: "/complete-subscription",
        });

        if (error) {
            console.error('error', error)
        }
    }