Navigate to SHOP -> Catalog and click Products to open your Products page, where all the products in your online shop are listed.
Find the product you want to copy and click Copy on the right side of the product row. You will be taken to the Add new product page with duplicated details of the original product, where you can simply change the desired data. This button is especially useful for adding products with variations.
Note: While most of the original product details are copied, you will still need to choose the category of the new product, upload its images and videos, as well as set the Variation settings and Attributes if you intend to use the copied product for adding variations.