'do you copy...?' (connection established)
'how do you copy...?' (signal quality)
'copy' (confirmation of received information)
'copy' is a confirmation in (wireless) radio communications. I wouldn't use it. It's... 'bad language' (/improper) among professionals.
The same as 'roger' (obsolete Army/Navy long spelling for : 'r', like 'received', originally used in morse code) or '10-4' (ten-four) in the US public safety (police) 'ten-code', meaning: affirmative, received, understood.