Take card payments through Stripe. Authorization runs BEFORE the sale completes: the till asks Stripe to charge the amount and only finishes the sale if Stripe approves. Set your Stripe SECRET key (sk_...) in the settings. For card-present payments, also set a Stripe Terminal reader id (stripe_reader_id) — the till drives the reader (Reader S700 / WisePOS E / M2, or a test simulated reader). With no reader id it runs an online/demo charge; in test mode amounts ending .13 decline. Card refunds are wired too: refunding a Stripe sale on the till refunds the original charge automatically.
Universal Till