You need to add the code to your child theme’s functions.php file or via a plugin that allows custom functions to be added, such as the Code snippets plugin. Please don’t add custom code directly to your parent theme’s functions.php file as this will be wiped entirely when you update the theme.

Use the following snippet to add a custom global product tab.

If you have custom field provided in your admin dashboard for your product, then the following code would be useful to achieve the required result.