Instagram online status

Hello people of the internet, I need assistance. How do I ‘show as offline’ on insta. I know I can hide when I was last online but is there a way to hide that I’m online, when online.

Essentially, A friend of mine is trying to avoid someone without blocking them, they’re not friends and have set their profile to private. They’re also turned off the activity statues. But how do they hide they’re online...

Many thanks in advance.