Vertical navbar that showing current section

I have a vertical navbar which located above.

When scrolling on screen, I want navbar to show current section automatically(as below).
For example, when I see the services section on the screen, I want to see the services text as green on the navbar automatically.

How can I accomplish this?

You can achieve this with anchor (aka “section”) links. But it’ll be up to you to style it as a vertical navbar.