Denied unemployment, how do I appeal? after 6 years as a payroll clerk

I got a denial letter last week saying I left my job voluntarily, but I was let go as a payroll clerk. I have read a lot of threads here and could not find my exact situation. 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?

Legal aid offices and some workforce centres help with unemployment hearings at no cost. A call is worth it.

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