Blurb does not use Freelancer.com, Upwork, or any other job site to hire translators or editors. Anyone claiming to represent Blurb over such platforms is a scammer. They will ask you for a deposit and steal your money. They may use the names "Sonia Lamster", "Joseph Madison" or "Reijnen".
If you're contacted by someone who claims to represent Blurb and offers you translation or editing work do not give them money. It's a scam. Please report them to the job site's support team.