Simplex accepts Apple Pay as one of the additional payment methods.
Once you reach the checkout, you can choose the Apple Pay option - this way you will not need to manually fill in your card details.
You can simply click on the Apple Pay button, then "Select your card" and agree to the terms and conditions - now you are all set.
Limits while using Apple Pay are the same as using VISA or MasterCard - the daily transaction limit is 20,000 USD and the monthly limit is 50,000 USD.
You can use Apple Pay with 16 fiat currencies - USD, EUR, GBP, CAD, JPY, CHF, KRW, DKK, PLN, SEK, ZAR, CZK, NZF, HKD, NOK, SGD.
You can find countries and regions that support Apple Pay here: https://support.apple.com/en-us/HT207957