That won't be a problem if you use the same unit scale. (Unity as convention is 1 unit as 1 mt).
So for example creating an array of Vector3 we can pass then the positions we want just on the X, and Z axis.
The current positions are of 1 Unit length, and will form a square, if you keep the same scale between the 2 project you wont have any problem.
What you need to do is now to export that Vector3[] positions as Json, import it and set the LineRenderer Positions.

To read more about it (with code example), check the source