A website notification can look like a system warning even though the message comes from a site you previously allowed. Closing its tab does not necessarily revoke that permission. Start by identifying the sender rather than clicking the alert’s repair or support button.

Record the website name shown on the notification. You do not need to visit the advertised page or call its number to change Chrome’s permission. If a screenshot is useful for support, hide personal information elsewhere on the screen.

Review the allowed websites

In Chrome, open Settings, Privacy and security, Site Settings, then Notifications. Find the unfamiliar or unwanted website among the allowed entries and block its notifications. Review the address carefully: a name that resembles a familiar company is not evidence that the site belongs to it.

Consider your default preference for future requests. Quieter messaging reduces interruptions from permission prompts while still allowing you to decide when a trusted site needs alerts. A meeting service may be useful; an unrelated page demanding permission before showing ordinary content deserves scrutiny.

Observe the result before changing more

Continue normal browsing and check whether messages from the blocked sender stop. If new browser windows or search redirects continue, record those separately. Notification permission and pop-up behaviour are different controls, and installed software or an extension may need investigation.

Blocking the messages prevents that notification route; it does not undo information already entered on a suspicious site. If you disclosed account details or installed a program because of an alert, include that fact when seeking help. Avoid describing the computer as clean solely because the alerts have stopped.

Source: Google Chrome Help.