How do I add variants? I don't see the "Pricing and variants" tab

Site URL: https://www.4x3d.com/shop/p/ad07jrsaa1irgg1ot6p34t0ieo6k53-kdnxk

I want to add product variants but I can't find the place to do that. I've looked this up. I saw several videos depicting a "pricing and variants tab" is this a pro feature?  I don't have it.

Just figured it out, doesn't work for digital products. To bad, that really sucks.