I'm only a layman casual, but I have never in my life seen an actual peer review.
I've read/skimmed actual papers from primary sources whenever I actually care to try to understand the proof for something. No idea what a peer review looks like, no idea if the paper I read were ever peer reviewed.
I'm guessing maybe the publisher itself also/sometimes does the "we read it, looks fine"-process? Either way, I've never seen one. They're like some mythical creature I've only ever heard descriptions of.