Hi there,
Its good that you realised soon after submitting and then emailed your supervisor quickly!
Hopefully, if they didn't make a big thing about saying it needed to be put at the end then it won't be too much of an issue, especially if your supervisor knows that you definitely already did the lab training. I think all you can do now is wait for a response and see!
On the other hand, it is likely that you will be downgraded for this, as it was mentioned in the diss guidelines that it should be included. Do you have access to the marking rubric for your dissertation? Usually they split each section into a certain number of marks. For example, this is how my dissertation was marked:
Abstract - 10 marks
Intro - 20 marks
Method - 20 marks
Results - 20 marks
Discussion + Conclusion - 20 marks
Structure, grammar, referencing, appendices - 10 marks
If yours is being marked a similar way, it is highly likely that you would only lose a max of 2-3 marks for missing it from the appendices, if that. Lets hope for the best though and that your supervisor says its okay!
Hope this puts your mind at rest a little? Good luck!
Jorja (LJMU Student Rep)