I understand that. Please read my question again. It is not about how can I expose my URLs to internet. Server is already setup. For testing purpose, Im using localhost.
Callback URL will be called when
a) user install app for first time
b) app is already installed and user click on that app in store. https://shop-name.com/admin/apps
My question is that is there any way to figure out if callback url is called to install app or opening already installed app. I hope you will understand my concern now.