Problem with the size of the Terrain in Pathfinding [ Unity 3D ]

I am producing an RPG.
The land is [2000x2000] but is giving problem, almost Unit stops running and is also very heavy.

Out that neither is running at 2000x2000

How can I use Pathfinding on a plot of this size?

Hi

What graph type are you using?
If you are running it in the editor, make sure “Show Graphs” is disabled since drawing gizmos for the graph is very slow.