If I understand your question, you were trying to create an ethereum wallet with binance dex, if youare trying to restore back your wallet on binance dex. This guide will help you.
Jump to step 6
https://link.medium.com/yb5e15Qq58w
Binance DEX works on top of Binance Chain and not on Ethereum blockchain. You can never create a wallet in an interface like MEW and use that to unlock wallet through Binance DEX or vice versa. Both works on separate blockchains! Also the tokens traded on Binance DEX is of BEP-2 standard and you can never withdraw them to any ethereum address which allows us to store only ERC-20 token standards. Jump to step 6
https://link.medium.com/yb5e15Qq58w
Not sure where you have taken the link from, but the link is dead actually and redirects only to Medium website.
However, if you are trying to create Ethereum wallet for your tokens, binance dex isn't good recommendation, try using myetherwallet.
You can never trade ERC-20 tokens (based on Ethereum Chain) in Binance DEX unless the token has swapped a portion of its supply for Binance Chain like NEXO for instance.@OP As BitMaxz said, if you have balances you can withdraw them from Balances page. If this doesn't work, trade the BEP-2 tokens for BNB and move them to Binance and withdraw from there.
so I should be able to just open this wallet somewhere like in Electrum or any other wallet and access it from there"
Electrum? Electrum doesn't support BEP-2 bitcoins AFAIK! I think we should swap BTCB to BTC through Binance centralized exchange before we withdraw our BTC! 
