With Stripe connected and the payments toggle on (Settings → Patient portal), patients see their PMS balance in the portal and can pay it by card. Payments settle to your Stripe account.
One honest detail matters: your PMS owns the ledger. DreamCRM records the payment and shows the patient an "as of" date, but the front desk posts it to the PMS ledger like any other card payment — the next sync then reflects the updated balance. Each payment records the balance the patient saw at pay time to make reconciliation unambiguous.