Maybe this post helps (although the original is german there is also an english translation).
Some hints can also be found in the docu.
https://docs.kurviger.de/route_transfer/transfer_to_garmin
Maybe this post helps (although the original is german there is also an english translation).
Some hints can also be found in the docu.
https://docs.kurviger.de/route_transfer/transfer_to_garmin