https://toptout.me - exists and handles a lot of these problems, if not looking to create a new wheel.

Though if you just want a simple ENV var that handles this WHILE honoring the specification on this page: https://github.com/alloydwhitlock/do-not-track-cli

Advertisers chose to ignore DNT because they claimed Microsoft making DNT enabled by default took agency away from the user. In reality, they probably weren't going to honor it anyway.

Love it. This is an annoying problem and likely the actual solution than asking folks to use a universal one. I'll put something together as a starting point.