post https://api.webflow.com/v2/collections//fields
Create a custom field in a collection.
Slugs must be all lowercase letters without spaces. If you pass a string with uppercase letters and/or spaces to the "Slug" property, Webflow will convert the slug to lowercase and replace spaces with "-."
Only some field types can be created through the API. This endpoint does not currently support bulk creation.
Required scope | cms:write