If you want to simplify your checkout fields to only grab the most important info from your customers, or add more fields that are related to your funnel, you can do so editing the checkout page step in your funnel.
In the Edit Step window, scroll down to the Checkout Layout panel. Click on Checkout Fields.
Tick Enable Custom Field Editor.
When this is enabled, you can remove and add custom fields, as well as change which fields are required or not.
Required Fields
You can set a field as required / not required by clicking on the blue down arrow beside the field name.
Check/Uncheck the Required field.
Remove / Hide Fields
To Hide a field, click on the Eye icon before the filed name. Click it again to Unhide.
Add Custom Fields
To add a new custom field, scroll down to Add New Custom Field.
Click Add New Field.
Don’t forget to click Update after your changes