The Route 53 Hosted Zone for wellcomelibrary.org is defined in an AWS account managed by D&T.
You can get to the Hosted Zone by assuming the following role: arn:aws:iam::267269328833:role/wellcomecollection-assume_role_hosted_zone_update.
You can see the Hosted Zone by going to https://console.aws.amazon.com/route53/v2/hostedzones?#ListRecordSets/Z78J6G8RSOLSZ
(You can't find the hosted zone in the Route 53 console because we don't have the ListHostedZones permission – some of them are for domains we don't control.)