Airtag with MacBook Air ?wrong advice in store

I visited apple today (approx 1.15hrs from where I live) and had a conversation with a guy in store. I told them I only had a macbook air, no phone etc. and wondered if I could use an airtag with it. I was told no problems it will work fine. Went away and jad a think, then returned later to buy one.....got home and opened the pack, pulled the cover and the airtag has bleeped so appears to be working. My macbook cannot find it on bluetooth/wifi and am unable to set it up. Following a search online it ??appears that it cannot be setup using just a macbook.....

Apple can you reply to resolve this thanks.