How do I completely disconnecy my iphone from my my macbook? (Example and picture in the description)?

Every time while using my iphone, like if I'm on safari for example. Someone else who is using my computer will see a tiny notification every time I visit a new page on chrome and if they click on the notification, the website that I'm on will also appear on the laptop. This is not only on chrome, but also for messaging applications as well, so how do I get rid of it (pic below) How do I completely disconnecy my iphone from my my macbook Example and picture in the description

"Someone else who is using my computer will see a tiny notification"

On the Mac, create a new user account for this someone, log out, let the someone log in.

Why do you allow others to use your login account on the Mac?