When the domain is locked, you won’t be able to either change the nameservers or transfer the domain to another service provider.
Steps for unlocking or locking a domain
Select the domain under your services and click on Manage;
Then, under Registrar Lock, click on Domain Lock Settings:
To unlock the domain, you need to choose Off, to lock the domain, you need to choose On:
Then, you need to click on Save Changes.