Is it possible to draw a 2D rectangle in the editor and save it as an area on an array?

I have created custom land tiles but now I’d like to build a system that’ll let me draw out areas for things to spawn in. However, I’m not 100% sure how to do this. I know that setting spawn areas is possible in code, but right now I’m using purely random placement.

You can use empty GameObjects and add a script to set stuff to spawn with math based off the position of each object. Make one then save it as a prefeb. Then you just tweek their location until you have the screen covered or what ever you need.