Did this start out as a pop up on your screen? For future reference, if that happens, you want to hold down Ctrl+Alt+Del, then launch Task Manager, and then end all browser items there to close it. That page is definitely scam, but as long as you didn't call the number and engage in any of the requested activities, your computer is not hacked. It is just a pop up page that can have some audio effect (sometimes) and display in full screen mode, so it appears the computer is locked.
Scammers use various methods to trigger these pop-ups. Pop-ups are a form of online advertising. They are often integrated into websites or applications through ad services. Many websites use third-party advertising services to display ads. Sometimes, these ad services might inadvertently allow scam ads to be displayed. This does not mean the website itself is malicious, but it indicates a lack of stringent ad vetting.
Microsoft is fully aware of this type of IT support scams and have an educational article about it here. The article also includes link you can report. https://support.microsoft.com/en-us/windows/protect-yourself-from-tech-support-scams-2ebf91bd-f94c-2a8a-e541-f5c800d18435 I do want to gently remind you though, Microsoft does not run law-enforcement or investigate individual scammers. But reporting can help Microsoft identify and shut down scam infrastructure over time, not about policing the scam directly.