The addons folder is empty in the GodotProject.zip file. So it can't load any Dialogic files because they are not included. I think the same goes for the web version shown on top here. It all means no dialogue shows up when entering dialogue area. It would be very nice to have it fixed. If (re)using Dialogic is an issue, I can recommend inkgd
Viewing post in Ninja Adventure - Asset Pack comments
I don't know if the demo used the dialogic plugin, I think I wanted to use it but I finally changed my mind, the dialogs probably never worked in the demo but it's possible that the project incorrectly deleted the dependencies of the plugin.
I recently worked on an updated version (with Godot 4.0) I should have a few days available this week for us to release the next update and this new Godot version.