Have AI ask questions to give the user a better answer

Hello, i am looking to build a chatbot that can help the user with getting government grants to make their homes more energy efficient. There are many types of grants and they depends on the state of your home, year of completion etc. I would like the chatbot to ask the user for the missing information when they ask about a particular grant. There are so many grants that i am not able to build a flow to cover them all. I need to AI to be knowlegable about all the requirements