How to add a shipping calculator to product pages created using custom templates or page builders
If your product page has been designed using the standard hooks for WooCommerce product pages, then this should work as predicted. However, if it is not working for you then there are other ways to insert the shipping calculator.
This article provides advice on the best way to insert the calculator, depending on how your product page has been designed.
Custom single product page templates
Block-based product pages using Gutenberg and other page builders
If the Position option doesn't work then you can either use the
[shipping_calculator] shortcode or a PHP function.