If you're already using automatic discounts. This is a neat little feature to ensure customers are aware of the discounts being applied to their cart. Take your automatic discount URL and append "?dt=Custom+text" to change the content that appears in the popup.
This will display a popup with your discount and the "Custom text" message
In Admin, go to Discounts Shopify find the discount you want to share
Click into the discount you want to share
Click Promote > Get a shareable link > Copy link
Add "?dt=Custom+text" to the end of the link
For example if you want to add "Save 10% storewide" to your popup your shareable link should look like this:
