How to give a new REDUIX item a unique ID?

I am mapping an array of data with props into a component. Then onClick I pull some of that data into redux/reducer from the rendered items, trying to render the same data – but in a different spot on the page.

My problem is (I assume?) that the ID’s are the same – I render data with keys’s/id’s that were already taken – while React wants unique ones.

I am not sure, if that’s what’s causing the problem – but I keep getting a warning that react wants unique key props.

(it’s a shop app – on click, i want to add the chosen item to a cart with redux… )

Thoughts?