Got a denial letter for unemployment, what now? after 18 years as an accountant

I got a denial letter last week saying I left my job voluntarily, but I was let go as an accountant. I have been trying to stay organised about it. My employer's version of events does not match mine, and I have emails that show it. Did you bring documents or only talk?

Thanks for writing this out. I went through something close to it 14 months ago, and it got easier once I kept a simple log of every call and form.