Common practice with insurance claims.
Insurers will not pay the VAT element if the claimant is VAT registered.
Search for 100% VAT ... there are quite a few threads & a couple of different methods.
Personally, I enter as two lines:
(1) Repair Cost = £100 with 20% VAT Code = £120
(2) Paid by Insurer = --£100 with 0% VAT Code = --£100
Net result is £0 Cost but £20 VAT.
Hope this helps.