That is what I got yesterday when downloading from the editor (asset store) we don't see everithing on the screenshot but I hope it can sill help you.
Then, when I enable the addon, I got other errors. If I remember correctly,they where about some files that do not exist. That's why I was able to fix them by changing 2 lines on the addon script:
By defaul, the pathes inside the script ended by talkietalkie_*.gd (I just removed 1 "talkie" in the beginning of the name to match what I see on the folder)
After reloading the project, I was able to enable the plugin without getting errors ! So, I tried to generate a presentation with project > tool > TalkieTalkie: generate presentation. first I had to add a node to my scene but even after that the generator complained about something else I don't remember (sorry).
Today there is a good new: the generator didn't complain any more and generated a scene. So as I don't get the last problem anymore I can't tell you exactly what it was.
I hope this description helps !