Problems with the language displayed within the App Store.

Within Apple Connect, the application’s language is Spanish (Spain). But in the App Store, English is the language of the application. According to Apple they are different things.
Apple says the problem is in the Xcode settings. I don’t use Xcode. Use Solar 2D / Corona SDK.
Is Apple right?
How do I configure Solar 2D to change the language to Spanish within the Sore App?

Thank you. Your answer was very helpful. I didn’t know that if there was no localization folder, it defaults to the English language.
Thanks again. It is appreciated.