Ernesto Speaks!

So the way that you will get your dog to bark on command, is to show them the food and withhold the food encourage them to make any little noise. In the beginning they might lick their lips and you can treat them for that. Or they might huff or sneeze, or take a big sigh, and that you should also reward because they're collecting their breath.
You can even reward them if they burp! And definitely reward them if they whine or growl.
When the dog wants something but feels restricted in their movement, they'll project the bark forward. Having them on a back tie or even getting them collected on their place will help. And to better understand why all of this works, I would suggest reading "How Dogs Work" by Raymond Coppinger. press.uchicago.edu/ucp/books/...

[@marsha7260]

The book sounds interesting.

[@caninemovementlab]

It's a bit dry and scientific, but I think it's important to read.