Appeal deadline questions after an unemployment denial after 10 years as a graphic designer

I was told my separation was for misconduct, which is not what happened. I would rather hear the honest version than the polite one. My employer's version of events does not match mine, and I have emails that show it. If you have appealed before, what helped you prepare?

Stay calm and stick to facts. Mine lasted about thirty minutes and felt more like a conversation than a trial.