When writing constants, it is a good idea to use const. For example, suppose we write

val MY_API_KEY = "API_KEY"

The Java code is

public final class MyConstKt {
   @NotNull
   private static final String MY_API_KEY = "API_KEY";

   @NotNull
   public static final String getMY_API_KEY() {
      return MY_API_KEY;
   }
}

The Java code has a getter. The getter exceeds what we need. Instead, suppose we write

const val MY_API_KEY = "API_KEY"

The Java code is

public final class MyConstKt {
   @NotNull
   public static final String MY_API_KEY = "API_KEY";
}

This code is the customary way to write constants. The class has no getter.