Hello, I am writing an online store on JS + Node.js, do I need to enable automatic qiwi payment using the API?

Question

Node.js

It is necessary to connect Qiwi payment using API (with automatic payment verification), the documentation normally does not explain anything. It is necessary that when the user clicks the button, he will be redirected to the payment site or popup form. I can't figure out how to implement it. If someone came across - help