How to add or change models / variants in particular product?

You can choose only specific models or add new ones in all of your products. To do that go to "Products" and press on three dots next to the particular product. Next, click "Edit" to make amendments. 

Once you are in editing mode, click on a list of Models selected. Check all models you want to have in this specific product. (In this example we have a product - Tough phone case with the design of mountains). When you are done, click on "Continue to Product Details".

In the next step, you can review and update information about the product. If everything looks good, you can click on "Save Changes" and you are done!