Thanks for posting in the Community, Pooksly,
Let me get the help you need to ensure that the purchase and reclaimed vat amount will show on your VAT return.
To start, upon creating an expense transaction, make sure to choose the 20.0%S VAT rate. This rate is the standard rate used for most goods and services.
Here's a screenshot for more detailed information.
Once done, pull up the VAT return. This should now show the purchase and reclaimed vat amount.
That's it! For more detailed information, you can check out this article: UK Flat Rate Scheme: How does it work?.
As always, if there's anything else you need help with, please let me know. Have a great day!