SPOILER WARNING. There seems to be a bug. I guessed 'rhyme', 'build', 'tonal', and 'local'. Then it said that I must use an UNDO. It doesn't let me enter 'vocal' and 'focal' to win.
The goal is to avoid entering the word. In this case 'focal' was the word. You entered 4 guesses, but only had 1 valid guess, + the 'wordle' left so it was impossible to finish without undoing.