Welcome.
I had to Google the Song and listening to it there are layered Fx applied particularly to the Bass notes.
Tried looking for the sheet music score but my usual sources came up short.
As a starter on an Arranger I would suggest:-
I would have a Reverb fx applied to the whole of the keyboard where the same piano sound would be used even though I would then apply a split, to the left of the split point I would apply another Reverb to the piano sound and then I would modify the piano sound to have a far longer release and decay to almost the same level as a Sustain pedal would produce.
I have tried this on my Korg PA700 where I used the Bright Hall Reverb Preset, I used a standard Grand Piano and adjusted the Decay to +27 and the Release to +20.
Now the thing is I do not have enough knowledge on the capabilities of your keyboard which is a few years old (current version is the 463), go to Function > Category and Select Reverb, try each until you find one that is as near as you can get. See your manual page 41 for info on theReverb and how to adjust the release.
This is the Youtube upload that I found
Interesting to read others take on how to replicate the sound.