Creating a pickerFieldCustom with a REST API result

Hello World,

In the Appian interface I am working on, I need to create a user picker. I can't use the default pickerFieldUsers component because the list of available users come from a REST API call. So, I am thinking to use a pickerFieldCustom component but I don't know how to build the suggestfunction property with the REST API call result.

Any help will be welcomed!

best,