by Store Boost Kit on WordPress.org
Add a Notify Me button for out-of-stock items. Store owner gets the list, user gets email when back in stock.

General settings panel where you configure the plugin.
Recover Lost Sales – Automatically bring customers back the moment products restock instead of losing them to competitors.
Build Customer Loyalty – Keep shoppers engaged and create urgency. Show them you value their interest.
Understand Customer Demand – See which products customers want most to make smarter inventory and purchasing decisions.
Professional Branding – Fully customize emails, sender details, and templates to match your store’s identity.
Simple Setup – No complex configuration, just install and go.