Without context, yup and yep are informal ways of saying yes. I've never heard of yupe. Maybe you could explain the context?

agree with eve on yup and yep being informal. I've noticed girls tend to say yep and boys tend to say yup but there's no traditionally assigned male/female roles for the words. Wondering if 'yupe' would be pronounced like "yupeee", like "yipee" that someone might say when excited but the 'yupe' word is rarely used, if ever. At least in West-America

I've also never seen 'yupe' before. Googling it shows nothing either.