Figma Simple Design System - How to add new options to drop down list (Input/Select Field)?

Hi!

Really hope someone can help me. I’m using Figma Simple Design System, specifically the component  Select Field under Inputs.

Does anyone know how to add more items to the drop down list? I can’t seem to find any settings for amount of items and when I try to copy and paste an item it ends up outside the instance. There must be a way of doing this that I’m missing?

Thankful for some help!

Jonna