I can import the HD account into electrum and get all the addresses and corresponding secret keys, but I can't find there the local trader account address.
Moreover, the paper backup of the local trader account address has the secret key encrypted (I don't understand the purpose of that). How do you extract the secret key from the paper backup?
Is there another way to get the secret key of the bitcoin address of the local trader account?
What honestly do you mean about local trader this is mycelium section where only mycelium walle only are here maybe you are talking about bitcoin account from some traders .. i think there is no trading site are giving you private keys/secret keys they are just exchange site and they are not providing any private keys or ways to backup or export secret/private keys.
Better to explain to us what is local trader account you mean,, ?