These are generally browser based redirects from some click bait link that someone has chosen to click.
Usually, launching Task Manager. either by right clicking the taskbar or by using Ctrl + Alt + Delete, finding your browser under the processes tab (all instances) right clicking and choosing to "end task" will generally do the trick.
Restarting is not often required although not a bad idea.
Avoiding calling any phone number or contacting by any means, any support provided by these types of "warnings" is always a good idea.
Think about it.....
I could probably help you, if you called me.
AM I going to give out my phone number indiscriminately to people I don't even know?
NO!
And that applies to most anyone, person or business who would likely be able to genuinely help you.
You would have to seek me out, just like you would have to do for any professional (plumber, electrician, carpenter, etc.,)
They just don't show up magically knocking on your door (physical or virtual).