You can cancel your subscription on Peacocktv.com/tv by following these steps:

• Visit the Plans & Payment section of your account.
• Next, click on the change plan button.
• You can switch to Peacock Free at the end of your billing cycle if you don’t want to pay any more for your plan.
• In addition to getting a confirmation on your screen, you will also receive an email confirmation (by email, it may take 2-3 hours or even longer).

For more details     Peacock.com/tv