How to make coins spawn randomly on my level?

So, I was making a small 2d platformer in unity. The core is that you have 30 seconds on a level and an enemy chasing you. I’ve made the score, so when I touch the coin, the score goes up by 1. How to make coins spawn randomly and how to spawn them in specific location/area where I want to spawn them in. *I mean that I want big spawn area where coin can be spawned.