Approach to add Price based Extra product options through Shopify App

New Member
1 0 0

Hi There,
From a long time, I am searching for the approaches to make extra product options or the custom product options along with its price  i.e Addons through Shopify App.
Specially incase when all 3 Shopify product options are already filled from shopify admin. i.e 4th product option with its price.
I am also curious about how the apps like bold product options or Infinite Product Options etc work behind the scenes.