Show best move in analysis

How do I see the best move for a given position?

Common use case: It shows me that my move was a blunder, and it shows what the best move was. But I don't understand why my move was a blunder without seeing the best responses to my blunder, eventually resulting in a material disadvantage.

There's another thread referencing a "show best move" setting, but I can't find it. Is it a paid feature?

Think I found it kind of:

It shows the top 3 lines, so if you click there you can see the best responses and explain why your move was bad.

That said, if is there a way to have it display on the board in a quicker way? With diamond maybe?

I don't think so. But I really hope they implement it on Chess.com (similar to LC). With the Chess.com app, the lines/arrows of the best moves are displayed immediately.