Custom Popup App need to show when clicking the add to cart button

[Noushad-siddiqi]

Hi, I'm making a custom popup app for client so he can install the app and add the functionality of popup when clicking on add to cart button. I don't know how to integrate the app with the store.

Any assistance you can provide would be greatly appreciated.

[Zworthkey]

Hii, @Noushad-siddiqi 
Please check this link.
https://help.shopify.com/en/manual/apps/working-with-apps#install-a-custom-app
I think it will help you.
Thank You.