I want to create a ticket system in my website

I want to create a ticket system and robot bot system on my website in WordPress. Firstly, I will give a bunch of questions and answers sheets of excel to the developer. They should make a bot with code ( Not plugin) who can answer the questions. If the bot can't, Then he suggest to raise a ticket to the user. Then the user clicks on the link and creates a ticket with some fields which I required. I will get the email and I will reply to the user. The developer should also create a ticket system panel where user can check the ticket status and previous tickets All should be made by code not a plugin and all pages should be mobile friendly and optimized.