Below are instructions on how to cancel your on demand subscription. Right now, you can't suspend your subscription, but you can always cancel and sign up again later!
There are two ways to cancel depending on where you signed up, either the Web or In-App Purchase.
Cancel (Website):
You can cancel your subscription at any time by logging into your account on the on demand website. Click on the menu icon in the upper-left hand corner and select My Account. Next, select Manage Subscription. You can then click on Cancel Subscription. Please complete the form and click Confirm when finished. You will receive an email when your request is processed.
Cancel (In-App)
If you subscribed to the app through Apple, you will need to cancel your subscription directly through the App Store, as detailed below:
1. Open Settings on your Apple device
2. Select your Apple ID
3. Scroll down to iTunes & App Store
4. Tap on your Apple ID/email address
5. Tap View Apple ID, then enter your Touch/Face ID or password
6. From the Account Settings page, scroll down and tap Subscriptions
7. Choose your On Demand subscription
8. Tap Cancel Subscription. Next, tap Confirm on the Confirm Cancellation pop up.
Cancel (Roku)
You'll only need to perform this step if you signed up through Roku separately. Roku provides specific instructions on how to cancel via their website or the TV applications via the link below.
https://support.roku.com/article/208756478-how-do-i-manage-or-cancel-a-channel-subscription-