I am looking for a solution to place on my client's website where in, if someone clicks the WhatsApp button it'll goto WhatsApp and ask a series of questions for the user to answer. I understand this is called WhatApp Business Flow and I am looking for services (free and relatively cheaper) that can do this task. I came across seekflow and freshchat - what are the other solutions out there - is there an open-source version also ? If not , something under $5 a month for less interaction or a limit to the number of chats.