i opened my mac and its asking forpasscode wat to do and a mail id is given i mail over it for passcode help so it  replied with provide 50$ then they will send me passcode

Contact Apple directly, don't use popups or odd email links.

This item you show appears to be a scam. Unless you've un-

locked or jail-broken the product, there's no way they could

force you into this hold-hostage situation.

Maybe try to start in Safe mode (shift key held down) then

your Mac OS may ask for your user admin password to

start in Safe mode. You could then try again.

If you've set the Mac to use Two-Factor security, you may be

able to get past this fake scam. Or plan on taking the Mac to

an Authorized Service Provider or an Official Apple Store for

help. Usually this kind of problem may be caused if you've

not been careful with your AppleID or other online browsing.

Sorry that you've an issue; perhaps others may offer more advice.

Good luck in this matter...! 😐