We do not currently support a historical sync from Strava. If you connect your Strava account with Final Surge, only future workouts that you complete will sync over to our platform.
However, you can manually upload TCX files to Final Surge. If there are specific workouts that you would like to manually import from Strava, this blog posts details how to export your workouts in TCX format from Strava and then upload those manually to Final Surge: https://blog.finalsurge.com/faq-uploading-fit-and-tcx-files-exporting-garmin-strava/