Adding the Buy Button sales channel
If the Buy Button sales channel doesn't appear in the Sales channels section of your Shopify admin, then you need to add it before you can create a new Buy Button or embedded cart.
Desktop
From your Shopify admin, go to Settings > Apps and sales channels.
From the Apps and sales channels page, click Shopify App Store.
If applicable, then log in to continue to the Shopify App Store.
From the Shopify App Store, search for Buy Button, and then click Buy Button.
Click Install.
iPhone
From the Shopify app, tap the … button.
Tap +, and then tap Sales channels.
From the Add sales channel screen, tap Buy Button.
Tap Add app.
Android
From the Shopify app, tap the ☰ button.
Tap +, and then tap Sales channels.
From the Add sales channel screen, tap Buy Button.
Tap Add app.
After you've added the Buy Button sales channel, you can create a new Buy Button.