How to Design a Chatbot?

Hi together,

I was wondering whether you can help me with the following?

I am trying to design a whatsapp/messenger chatbot that only offers its service to users that enter a serial number they have obtained from another webpage. I was curious about your thoughts on how I could handle this without too much coding experience. The main questions are: How does the chatbot know that he only replies to serial numbers that are already existing somewhere (where can I store them?)? How does the chatbot receive the information from the webpage when a new serial number is generated?

As mentioned I have not much coding experience and design the chatbot in a chatbot builder (btw: which one should I choose?). I have read some buzzwords (e.g., webhooks, authorization tokens) but don’t really know how to connect all this.

I would be thankful for your ideas! 🙂