As normal with WPML you can see a column behind a product to edit the languages.
Now it is gone! So where to activate the function? In the screen-options > no WPML function.
Is there any documentation that you are following? No
Is there a similar example that we can see? No
What is the link to your site? food-machines.com
See the image. There is a column gone. With other sites wiht WPML there is a clolumn to edit the other languages. There must be a hidden option to show it. Not in the WP Screen options, there this option is also missing
Products differ from the other post types (Page, Post, etc.).
I attached 2 screenshots below from a test site that I created to show you this - as you can see, for "Pages" we have those buttons, for "Products" those don't show up and that's the way WPML + the WooCommerce Multilingual add-on works.