Version 1 - Do 2 buttonholes as described to make gray version
Version 2 – The green version doesn’t have buttons, ends are grafted together. Do a provisional cast-on and graft ends together or do a three-needle bind off if you don’t want buttons.
Version 3 – Don’t add any buttonholes and just use the holes from the pattern itself as buttonholes.

Gauge is not overly important, you need a sturdy fabric.
I used bulky yarn; one test held two strands worsted.

Notes not included for provisional cast-on, grafting, or 3-needle bind-off. Many excellent tutorials available online.