This only applies in some cases. Amazon started collecting and remitting UK VAT on sales which are:
a) delivered to UK customers from outside the UK with a value of up to £135, or
b) delivered to UK customers from the UK, where the seller is not a UK business.
https://sellercentral.amazon.co.uk/gp/headlines.html?id=GWV6MZJ7MXL5Z6P2
When this is the case, you see tax transaction types with "Marketplace Facilitator VAT" on your Accounts and taxes page.
Once it shows up, you may want to separate the marketplace facilitator VAT (VAT Amazon paid) and the regular VAT you still owe into two different accounts.