Ah, I figured it out! Thanks! I didn't realize I needed to select when there was only 1 enemy. I was also trying to slam each letter consecutively without giving it a space (1-second to register). Really love this concept and I really hope you polish this up and make it into something. I see a lot of potential with this concept.
My recommendations: When selecting a target, display their information either at the top or center of the screen. Show each letter's Morse code (instead of the one at a time). Remove the ability to click/use your potions. Make the player spell "POTION" to use it. Stick with that core mechanic and keep building on it.
Edit: And try and give a live feed of what the player has currently done. As they (dot) or (dash), throw it somewhere on the screen so they get some visual feedback.