Just to be clear, this is the Hangouts I'm talking about: https://hangouts.google.com
And this is Google Chat: https://chat.google.com
I have a Dialogflow Chatbot with a Hangouts/Google Chat Integration and I can call it just fine in Google Chat.
But when I try to find the same Chatbot in Hangouts, I can't find it.
I created a chat room in Google Chat to talk with the Chatbot, but when I open it in Hangouts, the Chatbot's messages don't even show up.
Does Hangouts not support Chatbots? Was it always like this or is it because it's going to be shut down?
Hangouts Classic does not support and did not support adding bots.
This is how Hangouts Classic was built and it has nothing to do with its update to Google Chat.
Bots are only available in Google Chat.