Appeal deadline questions after an unemployment denial - any advice?

My claim was denied after 21 weeks of waiting, and the letter says I have a short window to appeal. This is my first time dealing with any of this. 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?

File the appeal before the deadline, even if you are unsure. You can gather documents afterwards. That is the one part I would not wait on.

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