If you have installed S-Health on your smartphone, your data will be synchronised with S-Health after you accept. If you have not installed S-Health, you can synchronise your data with Google Fit. It is not possible to change this priority setting.
PLEASE NOTE: The company Samsung has decided that the Samsung app "S-Health" will not support data exchange with third-party apps any more, starting September 1st 2018. Unfortunately the synchronisation between the FITvigo app and Samsung S-Health (version 6 and newer) is therefore no longer possible.