Which auto upload is not working? There are three ways to auto-upload, BT via a phone, WIFI, or plugged into a computer via Garmin Express.
If none of these work for you, you can connect your device to your computer, wait for it to enter mass storage mode (shows a PC on the screen) then find your activities in the activities folder under the Garmin folder on your device. You can then manually upload those activity files to GC, Strava, etc...
