A domain is in a locked state when the information in the whois search tool shows the status clientTransferProhibited.
In this state, the domain cannot be transferred to any other registrar.
To unlock a domain, you must contact the registrar with which the domain was registered and request its unlocking.
It is possible that the registrar provides the customer with a website (control panel) from which the domain can be locked or unlocked (as is the case with cdmon).