Manual trigger for sync proces

Sometimes if I open the app (iOS) I can see several pictures which are not synced. Even if I go into the settings screen, nothing happens (WLAN is available AND it is recognized by the App - WLAN Symbol at the top right). At the moment I have to change the settings, if I’d like to trigger the sync process (I think, this is working??). It would be nice, if I could just press the sync-symbol right beside the number of pictures to be synced to start the sync process (and of course the check for WLAN, if this is a thing).