Rumors before the M2 release said that it used 4nm.
https://www.macrumors.com/2022/03/10/m2-macs-with-tsmc-4nm-process/
Apple says they use "second generation 5nm technology"
TSMC's website says they have 6 different 5nm nodes: N5, N5P, N5A N4, N4P, N4X
https://www.tsmc.com/english/dedicatedFoundry/technology/logic/l_5nm
So the M2 likely uses N5P, N4, or N4P. N4 and N4P are usually called 4nm in marketing material.
There's probably a leaker out there with more knowledge.
Sure, I was just explaining it because the whole 5/4 thing is confusing.