Domain Transfer Lock

Domain transfer lock is only available for certain top level domains such as .Co.uk

Check with the TLD registrar if it’s supported. This is not an aws limitation

https://www.plesk.com/wiki/transfer-lock/amp/

Hi,

Based on the error that you are getting it seems the EnableDomainTransferLock API is returning you "NOT Supported" error. The error "not supported" could be due to any of the below reason -

InvalidInput The requested item is not acceptable. For example, for APIs that accept a domain name, the request might specify a domain name that doesn't belong to the account that submitted the request. For AcceptDomainTransferFromAnotherAwsAccount, the password might be invalid.

DuplicateRequest The request is already in progress for the domain.

TLDRulesViolation The top-level domain does not support this operation.

OperationLimitExceeded The number of operations or jobs running exceeded the allowed threshold for the account.

UnsupportedTLD Amazon Route 53 does not support this top-level domain (TLD).

See also, https://docs.aws.amazon.com/goto/WebAPI/route53domains-2014-05-15/EnableDomainTransferLock

I'm not sure if this would help but you can read this - https://whmcs.community/topic/305532-registrar-lock-only-on-supported-extensions/

It seems for .eu domain not possible to lock it