This looks like it is probably a request for the future. Notation Help says, "When you are manually typing in chord names, hit the TAB key to advance to the next major beat..." There doesn't appear to be a way to have the chord symbol be on an offbeat. For example:
POR-1.jpg
Note that the C7 chord symbol is on beat 3, where ideally it would be on the offbeat of beat 2.
Ralph