Binding failure errors in the ListViewDemos sample

When running the ListViewDemos app, and navigating to "ListView with DataTemplate" or other views using "ListView.ItemTemplate", binding failures are repported such as:

_'ImageUrl' property not found on 'ListViewDemos.ViewModels.MonkeysViewModel', target property: 'Microsoft.Maui.Controls.Image.Source'_

I am new to Maui and trying to use ListView in the same scenario, but I run on the same issues and would like to make sure I am doing stuff properly.