Samsung Health syncing is unfortunately only allowed by Samsung for members with accounts in the US. The popular recommended alternatives are Apple Health on iOS or Fitbit on Android.
For people in other countries not in the US but who really want to use Samsung Health to sync , here is a workaround submitted by a member:
1) Create a US Samsung Account using a computer (very important, not the phone) and using a VPN connected to a US server.
2) Once it's created, I cleaned the data in the Samsung Health app (user and cache) and unlinked my old account
3) I don't know if this step is optional or not: I pulled off my sim card and kept the Wifi, also behind a VPN connected to US
4) I logged into Samsung Health with the account created in Step 1
5) I also cleaned data from Gyroscope app (I guess it's optional)
6) Made the sync between Gyroscope and Samsung, it should work
7) You can switch off all VPN and put back your sim card
More details in this Reddit thread: