I am trying to submit my vat return using MTD and have signed up with HMRC but following the instructions on here in settings and advanced I don't get an MTD banner

This is a reported issue, Nixx1966.

Some users are unable to turn on the MTD feature. While our engineers are working for a permanent fix, I suggest getting in touch with our customer care support so you'll be added to the list of affected users. You'll receive an email notification once a fix is rolled out. Here's how:

1. Click Help in QuickBooks Online.
2. Choose Contact us.
3. Enter a brief description of your issue, then click Let's talk.
4. Choose either Chat or Get a callback.

The chat line is open from Mondays to Fridays at 8:00 am to 8:00 pm BST. Then, the phone line is open from Mondays to Fridays at 8:00 am to 6:00 pm BST.

If it's all fixed, you can check this article on how to enable MTD: Authorise QuickBooks to interact with HMRC - MTD for small businesses.

Feel free to drop by anytime if you have other questions. We'll be glad to lend a hand.