Iphone lost and erase data no working

You're being SCAMMED. Do not do what they request. As long as the phone was signed into Find My and you used a Passcode, they CANNOT hack the phone and they CANNOT put your data on any market. DON'T COMPLY with the scammers demand.

Ignore it. Your phone can’t be hacked if it had a passcode on it.

However, Beware of a common phishing scam: You may get a text or email from “Apple” or “Apple Security” (or sometimes “Police”) saying your phone has been found and to click on a link to see its location. This is NEVER from Apple or from law enforcement; it is from the thief or fence to steal your Apple ID and identity. Delete any such message without responding to it. Apple never gets involved in lost or stolen devices→Avoid phishing emails, fake ‘virus‘ alerts, phony support calls, and other scams

Did you have a passcode on the iPhone? If you did, they cannot access your data unless you fall victim to their scam and you provide your Apple ID and Apple ID Password. So no, they cannot access the data on the phone. They just want to scare you into thinking they have in order for you be scared enough to give them sign in credentials they need to remove the Activation Lock on the phone.