Unfortunately, Garmin severely limits the amount of data available via its API. They only allow access to data going back 5 years from the date that you connect the service (so it’s a rolling limit in that new users today can get data going back to 2018 … but next year, users new to CityStrides will only be able to get data going back to 2019). I wrote a bit about it in Where are my older Garmin activities?