Synchronization is done automatically, but you can also do it manually going to MENU > Weight > Sync data now .
To check the details of your measurement go in Menu > weight > List and select the measure you want to check
Note - Synchronization is possible only if the scale is connected to internet. La synchronisation n'est possible que si la balance est connectée à internet. Otherwise, the measurement is saved in memory and will be synchronized as soon as the connection is restored.