"Can you tell me?"
it isn't. Report it. I get that duolingo haven't included all the possible "you" translations. Plus, there are many ways to translate every sentence in spanish, so it's understandable they don't have all possible options yet. Just report it and hope for the best, this people seem to be working really hard :)
me puedes decir
it's still wrong and is a basic answer that is one of the first anyone would think of. It should be automatic for them.
I wish I could remember they do not accept the most natural answer. I suppose I will miss it every time it comes up. It is not a memorable sentence.