Hugo Masefield

Hi! I have submitted by 23/24 return using the online service, however I subsequently realised that non-residents to the UK (which I am one) aren't meant to use the online service with HMRC and instead need to get an advisor to submit a return or use an online 3rd party software. Is it possible to retract my return completely and submit with the 3rd party software? So far I can only see how you can amend your existing submission on HMRC website, but not just delete it.