Add different variants to the same store product i.e. size, colour, material, sex.
Go to Store>Store Inventory>click on the desired product.
Tip. Make sure you have your desired attributes added i.e. colour, material, sex. Head to the options section top right to add these.
You can then set the desired attributes for this product. For this T-Shirt we're selecting colour and size to be set.
If you need to add new attributes head to store settings to do so.
Once saved you'll land back on the product. Click 'Add Product Variant' from here.
Now simply enter your desired attributes.
You can setup as many product variants as you require i.e. if you had Small and Medium T-Shirts to sell, you would setup 2 product variants, one for each size.