How do I get variations to show up on the parent’s page?

I have all my products and their variations created. It’s mainly body butters that come in 2oz and 4oz. They keep listing as separate items, and I can’t for the life of me figure out how to merge them all into one. I just want both options on one page.

What am I doing wrong? I created the variations when I created the parent. I tried to go back and add the ASIN as a variation on the parent, and it just created ANOTHER separate listing.