The Vice President frequently wears a pair of ankle boots by Prada. Here you see Ms. Harris wearing them on Election Day in Michigan.
The Prada Napa Leather Ankle Boot ($790, no longer available) features a 2.3″ heel, square-ish toe, and zipper on the inner ankle.
The Vice President has worn another block heel design by the brand, the Block Heel Suede Pump, seen below in an October 2019 video tweeted by Miryam Lipper, a spokesperson for then-Senator Harris.
The shoe has a rounded toe and 85mm heel (a bit more than 3″); a similar style is available at Nordstrom.