How I can reset the data of an app?

Hello. I want to ask how I can reset the data of an app, if it is not in Icloud? I made a mistake in a game that resulted in me not being able to open the game and when I delete the game and re-download it, I still can't open the game, which is why I wanted to ask if there was a way to completely reset the game data so I can then open the game? (So ​​you can completely reset the game progress and stuff?) (This game is also not in ICloud)

[Re-Titled by Moderator]