You can probably just buy a small roll of polypropylene or nylon webbing, a 12 pack of plastic buckles or 3d print them, and make a bunch for your friends as well for at or around the same price.
And a tip for new owners, there is an OK way and a better way to use this belt.
Flip the belt and you can pull it taut where it stays in position so you can thread the tail end back through. If it's the other way, it slips as you're mucking around with it.
On my belt, it's badge out. The tail hides the badge if you're lucky or the right size.