Loading Bar At Start Of Game

I know already how to create a loading bar when I load another scene, but how to I make a loading bar for when I open the game on my phone or computer? Like before the unty splash screen.

I think you misunderstanding something:

The unity splash screen is the first thing to ever show up on screen.

After the unity splash, you can put a loading screen for the 1st scene of your game.

To my knowledge, you can’t show anything before the unity splash.