Freehub with sealed/cartridge bearings

I decided to buy a new freehub and replace it myself, as the one I had broke down (started spinning to both sides). However, I didn’t realize the new freehub has sealed/cartridge bearings as opposed to the old one which had loose bearings… as I was doing this for the first time I didn’t even notice.

What can I use instead of the old cone that used to secure the loose bearings?

On the other side I still have the loose bearings system. Will this work or can it cause any future troubles?