To manage your FarmLens subscription, you'll first need to click on your name at the top right, then click "My Subscription":
You will then be taken to your billing page, which displays what plan you're on, if you're on a trial, when your next charge will be, and how much you will be charged. If you have a coupon code active, it will display text saying how much you will be charged with your discount (which can be $0.00). All subscriptions that require a credit card are set to automatically renew on their interval (monthly, yearly, etc.) regardless of if you have a coupon. If you want to cancel your subscription you can click "Cancel" under the text describing your current subscription.
Clicking cancel wil pop up a confirmation box confirming that you want to cancel. If you have any time remaining on your subscription, you will continue to receive service, but you will not be billed at the end of the current subscription cycle:
* Does not apply to subscriptions that do not require a credit card to sign up.