Javacript novice here, I've been trying to learn how to remove this annoying error I always get on Nike.com
I tried to remove it through adblock which I can't
The only way to remove this error is click the 'OK' button.

heres the script for the "OK" button

<button class="notification-button nsg-button nsg-grad--nike-orange" data-index="0">OK</button>

what script can have this button click every single time this button appears?

What about you create a timer that checks every x miliseconds if the button exists, and if so, clicks it?