Go to Dashboard/Profile (avatar, bottom of the left rail)/Profile…/Plan/Manage subscription — this opens a secure billing portal (hosted by our payment processor, Stripe) where you can update your card, switch between monthly and yearly, view past invoices, or cancel.
Cancelling keeps Pro active through the end of the period you already paid for, then your account reverts to Free — nothing is deleted, but pilots beyond Free’s limit may need you to choose which stay active (see "What happens to my pilots if I go back to Free?").
If the Plan card on the Profile page shows "You have free Pro access" instead of a Manage subscription button, your Pro was granted complimentary (for example, as a beta tester) rather than through a paid subscription — there’s no billing to manage in that case.