2FA notifications
Ensure to have a device enabled to receive notifications for your NoMachine Network account: download the NoMachine app for your mobile device and log-in to Network, you will be requested if you want the device to be added.

NoMachine supports Apple and Google push notification services, so the device must support Apple and Google Play services in order to be correctly notified.

Additionally, verify the following:

1. Check in device apps settings that NoMachine is allowed to receive notifications.
2. Check in NoMachine Network settings that the option to receive notifications is enabled.
3. If all the previous checks are correct, login to Network on the device (use the recovery code if needed) and toggle (disable and enable) the option to receive notifications in the Network settings.
4. If none of the above works, get app logs from Security settings.
5. As an additional verification, in order to exclude issues with push notification services, uninstall and install again the NoMachine app on your mobile dedvice, login to Network and accept the system request to receive notifications.
6. If you can't receive notifications on server connections, verify that the User Id in the configuration of Machine Network 2FA is correct,and be sure that you accepted the push notification for pairing request.

2FA settings client side (protect your login)
2FA can be enabled for your login via the NoMachine User Interface -> Network settings -> Login panel.

If needed, use your recovery code to login to Network. If you lost the recovery code, please contact us.

Otherwise you can enable it from your User Area on the NoMachine web site. Log-in to your User Area at https://users.nomachine.com by using your NoMachine Network User id (the email you registered for the service) . Go to User Area -> Account -> Two-factor panel.

2FA on server side (protect access to your desktop)
Open the server UI and enter Settings -> Network to enable 2FA for connections to the desktop. You can do that also via the remote server UI administration.
 

Step-by-step instructions to activate 2FA Authentication are available here:
https://www.nomachine.com/support/documents/activating-two-factor-authentication