not "on ps4" in that sense you can use livesplit on your pc and display it on a second monitor or use frame perfect on your phone

in terms of adding livesplit into a recording you will need to record your console gameplay with elgato for example and then put it all together in OBS on a pc

If you stream from PS4, you can enable a layout which includes a timer (it wont have any splits though, and it counts the livestream time, it's not a timer you can control).

If you have a pc, in addition to using a capture card to record the game, you can also use Remote Play to play the game from the pc, so you can record and add splits with OBS.