If you can honestly say that you did not receive the original Notice to Owner, you can fill in the TE9 form as required, email it to TEC and the Order will be cancelled back to NTO.
Which will then be re-issued to you and you can decide to pay or contest.
Or you can pay the £204 now.
But you only have a few days to action this, without doing one or the other, you will be getting bailiffs and far higher costs