Yes — you can cancel your subscription anytime from Settings > Billing. Your cancellation takes effect at the end of your current billing term: you keep access to your features until then, and you won’t be charged again. Beamer doesn’t refund the current or prior payments. Once you cancel, you’ll get an email confirming the effective date.
Looking to move to a lower plan instead of cancelling outright? See How to downgrade or change your plan.