Play Ps4 games on PS5 possible?

I know that you can play all PS4 games (except for ~ 10 PS4 games) on the PS5 in a somewhat optimized way, but here's my question, you can play physical PS4 games (Blu-Ray) on the PS5 by simply inserting them, I know that 😅, but can you simply download the games you bought digitally on the PS4 and play them optimized on the PS5? Or can you only play physical (Blu-Ray) PS4 games on the PS5? Lg.

You can also just play digital games on the PS5, but you may find that some new ones such as CoD Cold War need to buy an upgrade.