No. You don’t tell her.
You SHOW a girl that you like her through your sexual advances and Game, you never tell her directly. Although seemingly a trivial difference in semantics, the way you go about this makes a huge difference in a girls perception of you.
If you tell a girl you like her, the challenge for her instantly evaporates. You are no longer the prize, and more importantly, you have eliminated all of her social anxiety. She doesn’t feel a competitive need to seduce you away from other women. You have already claimed exclusivity.