Updated subscriptions

frontend/src/pages/subscribe/Subscribe.jsx

@@ -39,6 +39,7 @@ export default function Subscribe() {
     password: "",
     confirmPassword: "",
     selectedTier: null,
+    billingInterval: "annual",
   });
   const [error, setError] = useState(
     searchParams.get("payment") === "cancelled"
@@ -126,7 +127,7 @@ export default function Subscribe() {
         await refreshAccount();
         navigate("/addresses", { replace: true });
       } else {
-        const { url } = await createCheckoutSession(data.selectedTier);
+        const { url } = await createCheckoutSession(data.selectedTier, data.billingInterval);
         window.location.href = url;
       }
     } catch (err) {
@@ -245,7 +246,10 @@ export default function Subscribe() {
           Select the plan that works best for you. You can upgrade anytime.
         </p>
         <TierPicker
-          onSelect={(tier) => set("selectedTier", tier)}
+          onSelect={(tier, interval) => {
+            set("selectedTier", tier);
+            set("billingInterval", interval);
+          }}
           selectedTier={data.selectedTier}
         />
       </>