A not-pology or "fauxpology" is a form of rhetorical manipulation in which the speaker attempts to get social credit for making an apology while in fact failing to apologize at all. This usually takes the form of deflecting blame to others.
Where the speaker is apologizing for some action
X, a true apology is generally of the form "I'm sorry I did
X", expressing both an understanding that action
X was a mistake and implying an intention to not repeat the mistake and (if possible) to correct any harm done by action
In its most common form, a not-pology expresses not "I'm sorry I did
X" but "I'm sorry you got upset about
X" – basically villainizing someone else for calling the speaker out.