Rectangular Nav Mesh Agent?

I need a rectangular nav mesh agent, or a way to simulate it. Can I do anything like that with unity nav mesh or would I need to get a third party or build my own system from scratch?

Is there a reason like a trickiness to making pathfinding for a rectangle that made unity only use a circle, or is it because unity nav mesh system is just bare-bones minimum?

Good day.

With Unity, Nav mehs agents will be cilynders. At least to calculate paths, but you can use colliders to make collisions with a rectangular shape to make objects “cant fit” inside a zone.