If you don't want to call the customer and they don't stop in with their card, the only way to get the card number will be to send them an invoice for them to pay and they have to check the box to save their card when doing this, or it will not be saved as described here: https://invoice.stripe.com/i/acct_19wu0mFWv6e9Pjx5/live_YWNjdF8xOXd1MG1GV3Y2ZTlQang1LF9QQnNDOUNuVUJH...

Most customers will miss doing that - it is bad UX practice (user experience) to use that method as your way to put their card on file. The best practice will be to call the customer if they aren't going to be in person and get the card on file.

Other options would involve using the QuickBooks API and a third party tool such as DocuSign to capture card information, though I only know of DocuSign doing that with Stripe.