2021.10.15

I have linked the TATTA app to my Garmin device, but my running data is not reflected.

It can take some time before your data is reflected.
On TATTA, only data measured by your Garmin watch after you have established the link to your Garmin watch will be recorded, and no data measured by your Garmin watch before you have established the link to your Garmin watch will be recorded.
Your running data from your Garmin watch will be linked to TATTA not when you have saved your records on your Garmin watch, but after you have established a link to the Garmin Connect app.