How to create (specific) waves of enemies ?

I am currently building a tower defense. I would like to implement a wave system where I can choose the number of each enemy type as well as their order. I imagine you need to use a JSON file but I'm not sure how.

Recommend using a function to spawn enemies. The parameters would be type and number of entities.

You could use a project file if you want to make a long list of what to spawn at each level. This could be xml or json. You can use the array editor to save an array as json, and load it at start of layout.