Go to Settings, go to Shortcodes and Display Settings- section, click Display on Single Product Page Switcher and check the Product Page now. You can also use the shortcode for a single product page, but be sure to use this shortcode on a single product page.
Barcode Display Single Product Page #
Product type: Single
Product Type: Grouped Product
Product Type: External / Affiliate
Product Type: Variable
For variable Product, As the product changes, the barcode changes automatically