There is no jailbreak for ios 15 yet. Coolstar is hinting at releasing one soon, but it will only work up to iOS 5.1.1.
ios gets much harder to jailbreak after iOS 5.1.1. Seems Apple sealed off root access, or something like that, in order to make jailbreaking even harder! (Thanks a lot Apple)
Bad news for me too, because my latest phone is running 5.2.1
We may have to wait awhile for a jailbreak for our phones. Hopefully if Coolstar releases one, it will inspire some competition from unc0ver etc.!