I have an interface ILoginExt with an extension function Login.logout(). This interface is implemented by the class LoginExt, and another class Login delegates ILoginExt to LoginExt. While I can call the logout extension function within the Login class, trying to call it from an instance of Login in the main function results in an “Unresolved reference: logout” error.

Please find the program below

fun main() {
      val login = Login()
      login.login()
      login.callLogOut()
            
      //Trying to call logout extension function. But received Unresolved reference 'logout' error.
      login.logout()
}
        
class Login: ILoginExt by LoginExt() {
      fun callLogOut() {
            logout() //Extension function can call from Login
      }
}
        
interface ILoginExt {
      fun login() {
            println("ILoginExt -> login() called")
      }

      fun Login.logout() {
            println("ILoginExt -> login() called")
      }
}
        
class LoginExt() : ILoginExt