How can I make an Inventory System like Rust?

Hey! So ive been stumped for a while about how I can do this. Rust has an inventory system so you can pick things up by pressing e and then when you are in yout inventory you can click on the item and press use. Ive been looking for some other assets and example scripts that could help me find this but I am having trouble. Could anyone supply some code or help me out here. I prefer C# but JS Is ok

 

Have a base class Item that items inherit from. Have an Inventory on the player (probably a good idea to use inheritance here too so NPCs or containers can use it), and create methods that allow adding/removing items to the inventory.

That's the basic idea anyway, it's not exactly a small system that you can write up in a code snippet. Unity has a 46 minute long tutorial for inventories. 23 minutes I guess if you usually use 2x speed.