You can access these settings by tapping or clicking on the settings cogwheel and selecting 'Payments' from the left margin. In this screen you can setup any payment integrations (PayPal Here, iZettle, SumUp) that may be available for your platform and other tender types (card, cheque, gift card, Voucher etc).

If you do accept any of these tender types just tap on the 'yes' button for each tender type that you use in order to enable them on the POS.