How to change user language with Google Apps Script

If you have a paid Google account (not @gmail), you can change the locale of your user:

function updateUserLocale() {
  var userEmail = 'm@cooltables.online'; // Replace with user email
  var newLocale = [
  {
    "languageCode": "uk", // Ukrainian for example
    "preference": "preferred"
  }
]

  try {
    AdminDirectory.Users.update({ languages: newLocale }, userEmail);
    Logger.log('Successfully updated locale for: ' + userEmail);
  } catch (error) {
    Logger.log('An error occurred: ' + error);
  }
}

You need to enable the Admin SDK API” service. After you do that, you’ll have the AdminDirectory

After the successful code launch, wait a bit. You need ~10 minutes before changes will apply everywhere.