A FEW THINGS TO KEEP IN MIND:
Apple Pay:
will come up if the customer accesses the payment link on an Apple device or on a Safari browser
will not come up if you've enabled tipping
this is a limitation set by Apple...they do not like when something obstructs the flow of the payment
customer needs to use the Wallet app to use Apple Pay
Google Pay:
will come up if the customer accesses the payment link on an Android or IOS device or on a Google Chrome browser
will come up if you've enabled tipping
customer needs to use the Google Wallet app to use Google Pay
IMPORTANT:
The customer's credit card WILL NOT be saved on file if payment is made via Apple Pay or Google Pay
You need to send the customer a payable invoice (allowing them to pay online via a payment form) in order for them to have the Apple Pay or Google Pay option
this allows them to access the payment form on their device which in turn determines whether Apple Pay or Google Pay come up for them