잘 is an adverb means "well" and has nothing to do with "sleep" 지내다 means "live" 잘 지냈어요? means Have you been doing well? = How's it going? = How’re you doing?

Hello, Jessica! :) 잘 지 냈 어요?(X) -> 잘 지냈어요?(O) This means "How are you? or How are you doing? or How have you been?" Hope it helps.

are you sleep well? 잘- sleep or this is so can meaning How are you ( smt my friends so write, but I think here meaning Are you sleep well? )