Adding WooCommerce Product On Sale is easy as 1-2. All you have to do is edit an existing product from your WooCommerce store.
Go to your WordPress dashboard -> Products -> and Edit the product that you want to put on sale.
For Simple Product type:
Let’s say we want to set a discount from $99 to $79. Go to the General tab and fill in the Sale price field:
Product Page sale view:
For Variable Product type: