To play Letterle, simply tap any letter on the on-screen keyboard. You have no hints or indications if your choice is correct, so selecting the target letter will require some luck and intuition. Just try different letters, one at a time, until you match the randomly selected target letter. With 26 letters to choose from, you want to make the right pick in as few attempts as possible.
Letterle records how many tries it takes you to find the letter, so you can challenge yourself to improve your score by guessing quickly. Keep playing Letterle to test and sharpen your hunches.