How do i draw splines?

I basically have a 2d hexmap that is generated in 3d space.

I’ve done all(i think) the work leading up to actually drawing the spline, but I can’t for the life of me figure out how to actually draw it on the map.

I have a hexmap, and two random points on the map, and use a pathing algorithm to find all the hexes between the start point and endpoint and put them in an array.

I just need to take that array, with all of its given points(i have the actual x/y coordinates in terms of the actual map as well), and draw a spline that connects them all. I’d also like to be able to update the spline with a material to change how it looks preferably.

I understand that this is possible, but for the life of me i can’t understand what I need to do to actually get there.