Voila has a bit of a learning curve because the interface it renders for interactivity is based on ipywidgets. You cannot just use code that works in a notebook directly if it involves interaction.
Have you studied the examples at the Voila Gallery and tried to find one close to what you want?
Appmode is often easier to take a working notebook and convert it directly to an app served via MyBinder. There’s a demo you can launch using the launch binder badge there.
I note that once it is corrected (see below), your code example it works in appmode.
Note it is possible to launch directly into appmode via MyBinder URLs but it takes some hand editing of URLs. If you get to the point you have a working notebook that works as you want when you use the ‘appmode’ button to switch and are struggling with adapting the MyBInder launch URL, please post back here and we can help you work it out.
See more info at:
- How to transform a jupyter notebook into a webapp? - #2 by fomightez
- links at the bottom of my post here
Also, you should review how to post code at this site. Your example isn’t useable as it is presented to others. See advice & examples under ‘Inline code formatting’ and ’ Entire line code formatting’ here. Luckily it was short and easily fixed; however, you want to keep it easier for people trying to help you.