"legally authorized" is a correct and usable phrase in written English. It is used to indicate that something has been approved or given authorization by a law or laws. For example, "The company only allows employees to access certain areas if they are legally authorized to do so.".
"It is a legally authorized commemorative coin".
Under Israeli law, there are scores of legally authorized settlements throughout Palestinian territories.
A few weeks later, another deadline will arrive when the government bumps up against its legally authorized borrowing limit.
They said they had received consent for the operation from a family member legally authorized to give it.
Technically, mixtape samples aren't legally authorized, but since they aren't for sale there is little cause for action.
All patients or their legally authorized representatives provided written, informed consent.
Informed consent was obtained from the patient or their legally authorized, whenever possible.
Being a terminologist, I care about word choice. Ludwig simply helps me pick the best words for any translation. Five stars!
Maria Pia Montoro
Terminologist and Q/A Analyst @ Translation Centre for the Bodies of the European Union