What appeal?
Your NOR was dated 11 May. This places you on notice that you have the right to register an appeal within the 28-day period beginning on the day of service. This period ended on 11 June.
TfL cannot extend this period, it's not within their powers.They may extend the period before a CC is issued by them as this is their choice.
But not the appeal.
I am worried that you have missed the period for registering an appeal, in which case you have nowhere to go procedurally to plead any argument, whether substantive or technical.
Have you registered an appeal with the Tribunal? If not, then try today. You will need to include reasons for lateness which if accepted means the adjudicator may register your appeal late.
As far as I can see, these reasons would be that you were led to believe by TfL that all enforcement and appeals processes were delayed by 2 weeks while they provided you with the evidence which is central to your appeal i.e. the video of the contravention.
Wait for others.