If you are experiencing difficulty with the firmware update process with your Audient interface, you can use Audient dedicated firmware updater application to hopefully resolve the issue.
If your interface isn't shown, this would imply that it is not being properly detected, and you may need to try using a different USB port or cable.
Once successfully connected, click the device you would like to update then click 'Start Upgrade'.
The application will notify you once the update is complete (the process should take less than one minute in total).