@Dominic ******
you won't get anything back. You have 7 days from the day that you submit a TM30 to go back into the system and search for the submission you made. Once you find it you can click on the export button to generate a pdf. That is your proof of TM30. If 7 days passes you can no longer search for it and get proof so if you forgot or didn't save it, you would need to submit a new one and then search for it to print it.
As you can see there are many reasons people would be submitting TM30s all the time, even if they just need proof but can no longer access it.