Yes, they are the same thing. There are different varieties but the seeds are interchangeable. And particularly for cosmetic use I don't think you need to be concerned. You should be able to find whole flax seeds/linseeds in any health food shop, also Bin Inns. And I think the baking sections of most supermarkets would have them - can't remember the brand but it has pale green packaging. Healtheries?
https://shop.countdown.co.nz/shop/produc...lsrc=aw.ds
https://www.newworld.co.nz/shop/product/...lsrc=aw.ds
https://shop.countdown.co.nz/shop/produc...lsrc=aw.ds
https://www.newworld.co.nz/shop/product/...lsrc=aw.ds