Tribunal representative

Hi everyone, I received a negative decision and asked for a mandatory reconsideration, and it was the same. But that was May, and i did not have the energy for the tribunal. I want to go to the tribunal now, but I realised I should have done that a month ago. The letter says I can apply online with he details of a representative. Where can I get one, please? I have also been waiting for an ADHD and dyslexia assessment for about a year now, I dont know what next steps I can take?