All the ones I see online look to come off with a regular socket wrench. On this one it looks like I’d need a cone wrench to remove it. The threads for the trim piece is wider than the nut below. Does that seem right?Need a new cartridge as the o-ring is prob shot. The top half should spin out, possibly reverse thread, take to home depot and match up. But shut the water off first from the angle stop below the sink.
Unless you want to impress your wife for 2025 and upgrade the fixture, you can replace.