After you have purchased the Garmin version, you click the DOWNLOAD button to download a ZIP file. We recommend you download the ZIP file to a computer (not to a mobile or tablet). This is because you need to extract the ZIP file before you can continue.
After you extract the ZIP file, you will have a folder called "GPSmap.is 2021.30 Garmin" (or similar). Inside are two files:
(a) "GPSmap.is Iceland 2021.30 IMG Installer.exe".
(b) "gmapsupp.img".
The two files give you two different means to install the map to your device. The first is an installer program that you can run to install the map automatically. The second file is an IMG file (the map itself) you can install manually to your device.
Either way, you need to first connect your Garmin device to your computer via USB cable. The Garmin device should then be visible in Windows File Explorer as a new drive.
NOTE: If the device is not visible after 30 seconds or so, you may need to change the MTP Setting. See here.
It is important to understand that all Garmin devices need to have the IMG file (the map) in a folder either called "Map" or "Garmin". Usually if the device is older, the map needs to be in the "Garmin" map. Newer devices need the map to be in "Map" folder.
If you use the installer program, it will install the map in the "Map" folder if it exists, else it will install into the "Garmin" map. This automatic process may not work for all devices and you may want to do this manually.
To install the IMG map manually, then look for a folder in the device called "Map" or "Garmin". If the device is older, you just need to put the IMG file into the "Garmin" folder. If the device is newer, you may need to create a folder called "Map" if it does not exist and install the IMG file there.
That's it. Now it is installed and you can disconnect the device and start the device. Go to Settings > myMaps and select the map to make the map active.