Add mod dependencies

I want to add a OPTIONAL dependency to my mod, Iron chests, the reason is that this mod adds a NEW resource and i want to add a material chest (For Iron chests) But:

1. It needs to have LOTS of slots

2. I only want this if Iron chests is installed

I have zero knowledge of making minecraft mods, other than the blocks that MCreator creates, (But i have VERY good knowledge on other coding subjects, and i have used LearnToMod)

So, can you add a mod dependencies section please?