Author Field Guide
The Author field provides a drop down list containing authors (users) that have created content.
Field Settings
Header: Placeholder text for the first item in the drop down (value is empty). For example, "Select".
Multiple: Whether multiple values can be selected from the drop down list.
Form Layout: Choose the layout that will be used to render the field.
On Change: JavaScript function that triggers whenever the user changes the value of the element.