I'm Miles from the Social Care team at Shopify. Thanks for letting me know your Apple Pay buttons are not appearing on your device. There are a couple of rules set by Apple that will determine when Apple Pay will show, and I'll outline them below. Please check each of these and let me know if this fixes the issue for you.
To enable the Apple Pay button for your online store, you must meet the following requirements:
To see the Apple Pay button, your customers must use Safari on iOS 12.1 or macOS 10.14.1 on one of the following devices:
You also need to make sure of the following steps:
Lastly, please ensure you've got Apple Pay selected as an option with your Payment Provider. For Shopify Payments, you can check this by heading to Settings > Payments and clicking "Manage" next to Shopify Payments.
If you've checked the above and your still not seeing Apple Pay on your store, please let me know as we may need our technical support team to take a look at the account for you.
Thanks so much for getting back to me. I've had a chat with our technical support team and they would like to take a closer look at this for you. To do this, I need to access your account. I've sent you an email to the email address registered on this post. If you could please reply to that message I will get the ball rolling.
Are you able to provide the details of your site (your website URL will do) so I can check this out for you?
Can you also confirm you've read through this post and confirmed there are no issues with any of these steps and requirements?
I look forward to hearing back from you and helping out!