Under testing
Click here
Then enter your Api key and secret
https://demo-futures.kraken.com/futures/PF_XBTUSD
demo account api key
kuQh1QQVEkOJ7kvde5WdzlcYzsG8qWOlHjKxbbpTduEaPlhhrhaBlMvP
API secret
TglafBrcTPIIzD4V4fLZJTgcqWHdO+EUQJoMJXXmmejdp/xBjKpLDLa9MJaOsYSyNDwPtd0SqCgYwDIQohsyY2x7