My partner's Mac is being prompted to call a phone number

Thank you. I'm sorry I included a link in my original question. My partner was freaking out, so I used my own MacBook to ask the question. It was a website he never visited before, and the audio which accompanied the popup window was something new.

He does have malwarebytes installed so we ran the scan to assure him that all was well to ignore the scam.

He is not very tech-oriented.

Thanks very much for your confirmation.