Thank you for the answer. I believe I followed all of them and still its not working. BUT maybe i dont understand point no 8 correctly:
“To add product categories to your website navigation menu go to ‘Appearance – Menus’, ensure ‘Products’ and ‘Product Categories’ are checked under ‘Screen Options’ and drag and drop as required”
When I click screen options, I dont get any choises.. what am I doing wrong?