Where to check if stock can be purchased from tax free isa?

I have been looking at holding some nio but confusions had me that nio isn’t in isa tax free. Anywhere I can check what stock is in isa tax free account before I do it?

Before you do what?
Open an ISA?

Or do you already have an ISA?
If you already have an ISA you can just search for the stock in the app and if it’s not available in the ISA it will tell you.