Once you have your business submitted and approved for accepting Dagloyalty payments, it will be set as the default payment method for POS checkout in web and the POS (Android) app. Just create a POS invoice as usual and when your customer scan the Dagpay invoice QR-code, they will be required to make the payment with dagcoins purchased from a Dagcoin ATM or V-ATM. If a customer does not have enough coins to make the purchase, they will be notified in DagWallet and the payment won't be sent.
You can also configure the settings for Dagloyalty payments in Settings → Merchant profile, under the Dagloyalty payments section, or under general settings in the Dagpay POS app:
Enabled - Payments for all POS invoices can be made only with coins purchased from a Dagcoin ATM or V-ATM;
Ask - Creating a checkout asks you every time whether the generated invoice should accept only coins puchased from a Dagcoin ATM or V-ATM, or all dagcoins;
Off - Payments can be made with all dagcoins.
Note that as of now, Dagloyalty payments are unavailable for Integration and Email Invoice type Dagpay invoices.