You will need to roll the VAT return back firstly. If you view it, you should see the rollback button at the bottom of the page.
Before you create the new return, ensure that “Enable Online Filing” and “Use MTD Features” are both enabled in your VAT settings.
Lastly, when you create your new return, you should then see a box at the bottom of the page to submit it. Providing this is ticked, we’ll attempt to submit it for you.