Bertie
The DWP's submission to an appeal, which they will produce when notified of the request, will include all of the documents used in the making of the Decision, as a minimum it will include the ESA50 and any evidence that was attached to it and the assessment report.
The claimant cannot be required to attend, however, the panel may request their presence. If this happens it may be to the advantage of the claimant to attend, but they must also consider what issues might be raised if they do.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems