No Updater for Linux, you should use wine.
This is a reply from garmin support:
Thank you for contacting Garmin Europe.
I am happy to help with your enquiry.
Unfortunately we do not support Linux operating systems; we only support
Windows and MAC Operating Systems.
I'm afraid we do not have any plans to introduce this.
I'm sorry for any inconvenience.
If there is anything else I can help you with then please let me know.
Alternatively you can search for a solution here:h tt p://www.garmin.co.uk/support