How can I sync data from Samsung Health to Exist?
Exist doesn't integrate with Samsung Health directly, but you can sync your Samsung Health data to Google Fit, and from there sync it to Exist.
Syncing Samsung Health data into Google Fit is possible with an app called Health Sync. This app is not affiliated with Exist, and there may be alternatives available. Health Sync supports syncing lots of data into and out of Google Fit, including data from Samsung Health. Once your data is in Google Fit, you can set up Exist to sync from Google Fit from your services page.