I am a crypto/Ethereum newbie. I came across LocalCryptos (localcryptos.com), which is a non-custodial platform used mainly for trading ETH.
It says: Keep your funds secure by backing up your wallet. If LocalCryptos were to ever go offline, you can still access your wallet using this file.
My question is: how would I use that file to access my ETH wallet, if the site goes offline?