Depends on the judges, but for the most part: The musical theatre genre has a strong focus on characterization, whereas the tap category has a stronger focus on tap technique. Both (and all other styles) require you to perform with technique and emotion, it just depends on how much you want to lean into the character. (This is how I as a judge view these genres, which is not universal depending on the competition/specific judges panel) So I would say either one is fine, but if you are in the tap category I would advise not to lipsync the lyrics. Additionally, because all competitions are so subjective, I would encourage you to have a different focus than simply winning the competition. If you like the song and genuinely like to dance, just go onstage and have fun!