You can start using the Apple pay service only if you already collect payments in your E-shop with credit and debit cards, because apple pay is only an additional service. More information on how to do it you can find in FAQ section 14.01 Can I collect payments with Credit and Debit cards.
If you already have card collection turned on, but you don't see Apple pay in your online store, go to Projects & Activities > My Projects > Project settings > Paysera Checkout settings, and in section “Payment methods you would like to accept“, click on the countries where you want to enable Apple pay, put a check mark and click Save changes at the bottom.
Moreover, you have an opportunity to select whether you want new payment methods to be activated on your website immediately after their addition. To do that, simply check the box “Activate new payment methods after they are enabled in the system.“