There's no setting for the auto-accompaniment fingering type on PSR-E models. They automatically recognize a simplified fingering that uses 1, 2, 3, or more keys, depending on the type of chord you want.
To select a major chord, play 1 key-- the root note of the chord.
To select a minor chord, play 2 keys-- the root note, plus the nearest black key to its left.
To select a seventh chord, play 2 keys-- the root note, plus the nearest white key to its left.
To select a minor seventh chord, play 3 keys-- the root note, plus the nearest white key and black key to its left.
To select other chord types, play all the notes of the desired chord-- but sometimes you can omit certain notes.