By default on this script, manual/bank payment is available.
To edit your payment credentials for your available payment method, kindly navigate to the plugins page on the admin and click on the Configure button on the Payments Addon card. From here you would find all installed payment addon & edit if you please. You can add a new payment addon from that page.
Please note you can only use one currency that is supported by the payment method you select as this script does not have a currency converter. EX: Paypal, Stripe support USD among others whereas RazorPay supports INR.