Your computer is low on memory pop-up window
Is this a virus or malware? I of course choose do not allow.
How do I get it to stop popping up? It is happening ever few seconds after I click it away.
Question marked as
Welcome to the Apple Support Communities.
That is fake, possibly malicious, pop-up. First, force quit Safari: How to force an app to quit on your Mac - Apple Support. Next, Clear your browsing history in Safari on Mac - Apple Support. Finally, run a scan with Malwarebytes for Mac.
Also, go to Safari > Preferences > Extensions, and delete any.
Cheers,
Jack