GitKraken (as of version 1.7) does not seem to offer a way to get into a detached HEAD mode, and check out a commit directly. Similarly, it will also not allow you to check out a tag (since that would also give you a detached HEAD).
So instead, you will have to create a (temporary) branch first which you can then check out.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…