Adding text into the List Picker to Save

also, does anyone know how to add items into the list picker by entering text and submitting it? If you plz feel free to actually explain instead of just links.So sort of connecting the list picker to what I submit Thanks:)

  • copy the Elements into a list variable
  • add textbox.text to the list variable
  • copy the list variable to the Elements

Use this-

Thank you so much:)