What do you mean you don't have sx os menu? If you're using sx os, you ARE using sx os menu (and don't need hekate).
Anyways, go to sx os website (
https://sx.xecuter.com/), download latest sx ox and the sx loader payload file, copy the contents of the sx os zip file to your switch's microsd card, then push the sx loader payload file to your switch using tegrasmash while the the swtch's booted into RCM mode.