On Change

Change event element.on(event: 'change', handler: function) The change event is triggered when any value in the change event payload changes. The event payload always contains certain keys, in addition to some Element-specific keys. The following Checkout Elements support the change event: paymentElement, billingAddressElement, shippingAddressElement, taxIdElement, and checkoutForm. > Consult with your legal counsel regarding your requirements and obligations about how you collect, use, and store customers' personal data