Example of detecting Do Not Track on the client side

dnt-client-side-function.js

function isDoNotTrackEnabled () {
  const doNotTrackOption = (
    window.doNotTrack ||
    window.navigator.doNotTrack ||
    window.navigator.msDoNotTrack
  )

  if (!doNotTrackOption) {
    return false
  }

  if (
    doNotTrackOption.charAt(0)  === '1' ||
    doNotTrackOption === 'yes'
  ) {
    return true
  }

  return false
}