Denied unemployment, how do I appeal? (Seattle)

My claim was denied after 13 weeks of waiting, and the letter says I have a short window to appeal. I have not done a hearing before and I am nervous. 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.