The market is flooded with many platforms with ready made templates that makes it easy for anyone to create chatbots. To name a few ,platforms like ManyChat, Chatfuel, Mobile Monkey, Tidio etc provide the necessary tools and training videos to get one up and running quickly without coding. However, if you have a development background and want to use programming languages to create a chat bot, then there are technologies such as Python, Clojure, Java, PHP or Ruby.
A lot depends on the complexity of your chat bot and the features you’d like to add.The standard functions based bot that completes scripted actions are easy to build. The more complex AI-powered chat bots use machine learning to learn and improve their capabilities. Platforms such as Amazon Lex, IBM Watson, Azure bot or similar services could be utilized.
I hope this helps!