They demand payment (usually in Bitcoin) to prevent them from sending the video to your contacts.
Mark the message as "Phishing" or "Spam" in your email client to help their filters catch similar messages for others.
For more information on identifying these types of threats, you can visit the Federal Trade Commission (FTC) guide on phishing or community discussions on platforms like Reddit's r/phishing .
If the email included a password you still use, change it immediately on all accounts. Use a password manager and enable Two-Factor Authentication (2FA) .