Orders placed on the customer app are queued for Invoice, and won't be auto charged by card if the customer's default payment type is ‘Pay by Invoice’.

If a customer's default payment method is set to ‘Pay by invoice’ in the POS and the customer then places a Pickup and Delivery order online, it will not automatically charge the saved card on file. Instead, it will keep the customer on the invoice payment method.

Please see this article on how to set a default payment method for your customer: Customer Default Payment