Assuming you're using the same PSN account, if you go into your PS5 games (far right icon) You should see the game there. Click on it and it should just download the game onto your PS5. If not, go into your 4's menu where you have your memory list in terms of games. Go down the list and if it's on the hard drive select upload to the cloud select everything attached to that game, especially your saved data so that when you play the game onto the 5, you'll pick up right where you left off on the 4. Remember to pull down that data from the clod onto the 5. Pulling your saved data over is critical because many 4 games don't run that well on the 5 unless you bring over the saved data. If you need step by step, let me know.