How to do human fallback handover on Chatbot UI widget?

Ok firstly im planning to use a chat widget created by JitestGaikwad since the structure is very easy. but I want to add human fallback handover so when the bot can’t answer the user intent. It will transfer to me, maybe it connected to me via whatsapp or telegram.

What i imagine of the result is when I anwering the user question it display on the widget. So the user don’t need to open telegram or whatsapp to contact me

But idk where to start. Can anyone please give me a good reference material or tutorial?

(Sorry for the bad english)