This step can be such an important step for making the game you should notify this at the beginning. Ok, let's go with simple steps:-
1- Open the unity
2- Click edit
3- Project settings
4- Choose Android or ios
5- Player -> Resolution and Presentation, from the orientation ->Default orientation.
6- choose what you need. (For ex:- I made a 2d game and I chose just Landescap Right.
⭐Happy coding⭐
Tags:
Unity