Solution
The compatible variable for the list box selected item index is a numeric integer.
To get one of the items selected on the indicator, follow these steps:
1. Select the
List Box Indicator and press on the grey box.

2. On the Choose a Property pop up, press on
Selected Item Index.
3. After making a single numeric
Shared Variable in LabVIEW, set the connection between your computer and the iPad. Below is an example of the shared variable in LabVIEW.

4. After running the dashboard, the List Box Indicator will have the Selected Item Index highlighted.