The Source Language of my game is not English. So Players, that Mother Language of them isn't English can't play my game translated into English

I translated my game into English.
Because the Source Language of my game is not English.
But Players that Mother Language of them isn’t English can’t play my game translated into English.
Of course,
If I changed the Source Language of my game to English, they can play my game translated into English.
But I’ve made the game by Korean for long times with my teammates.
It’s too hard for Changing my game to me now.

Is there a way that they can play my game translated into English and I don’t need to change the Source Language my game?

Check out this article on the wiki! It will show you the steps on how to add multiple languages and their translations to your game.