Affiliate link/Add to cart button

Hello,
I have installed Woocommerce on my website. My Website is a Coupon or Affiliate website. I am looking for some help on having a function when any one click s on BUY NOW button or any of the Coupon button, system shoul give a popup to either log in or register. like this website here (https://goo.gl/ap2iPz) if you click on GRAN DEAL button system prompts the buyer to log in or register.

My website is https://goo.gl/eB6v3o

Help will be much appreciated.

Thanks

https://www.ads-software.com/plugins/woocommerce/