creating a website for customers to pick a number from a database

I want to create a super simple website where users are prompted to provide their name and phone number and choose between a list of numbers that we store on a database. After a customer submits submits his or her information, they get directed to a confirmation page and we receive a confirmation message on Whatsapp. Each number should be given only to one customer, and once the number is given to a customer it should be removed from the db.