For Apple Pay or Google pay checkout methods to be available, you must be using a compatible browser, device, and have a card saved.
Important: Without these, the web payment buttons will not appear in checkout.
The exact requirements for web payments to appear are:
Chrome (Google Pay only)
Chrome 61 or newer.
A saved payment card
Chrome Mobile for Android (Google Pay only)
Chrome 61 or newer.
An activated Google Pay card or a saved card (Settings > Payment methods).
Access payment methods enabled (Settings > Privacy).
Microsoft Edge for Windows
Microsoft Edge 16.16299 or newer.
A saved payment card.
Mobile Safari (Apple Pay only)
Mobile Safari on iOS 10.1 or later.
A card saved in Wallet, by going to Settings > Wallet & Apple Pay.
Safari (Apple Pay only)
Safari on Mac running macOS Sierra or later.
An iPhone (not an iPad) with a card in its Wallet paired to your Mac with Handoff, or a Mac with TouchID.