You can add a group of fields to your checkout using the Checkout UI extension. This lets you collect information for the entire order, not just for individual products. The Checkout Extension requires the Growth Plan, available only for stores on Shopify Plus.
- From your Shopify admin, go to Settings >Checkout.
- In theConfigurations section, clickCustomize next to the checkout you want to edit.
- At the top menu bar, select the checkout page where you want to add the app.
- ClickAdd app block.
- Click on theMagical Fields app block.
- EnableAllow app to block checkout.
- ClickSave.
After adding the app to your checkout, you can move it to your preferred checkout area.
That’s it. Your custom fields are now part of your checkout.
Originally from our Help Center