How to make a scheduled autoresponder in Viber?

Question

Automation

We provide technical support to customers in Viber. The account is registered to a working phone number. Sometimes a support person is not working for various reasons. How to make it so that when it does not work, the client who writes to the viber receives an automatic answer, like: Hello! I am on vacation, please write your request to e-mail such and such.
Alternatively, you can use a pinned message, but it works, as far as I understand, only in the community. The community is not suitable for work.
I tried a chatbot, but only a bot can communicate in it. There are services that switch communication from a bot to a live person. But you can communicate only through the web interface of the account of this service, which is not convenient. I did not find any services so that in a chat bot it was possible to communicate with a living person directly through viber.
Please tell me the solution.