Welcome and thank you for getting help with your VAT return. I'll share information about it.
As of now, we are unable to support VAT Refunds based on the condition you have specified. We only generate returns for companies that use VAT codes available in QuickBooks. Some of the codes have percentage of reversed charges, which will automatically flow on the form.
I suggest consulting a tax professional so that they can guide you on your return and ensure you stay compliant with HMRC.
You can also check out these HMRC articles about charitable institutions for your reference: