Add this line to build.gradle.kts(Module::App)

    // Splash screen
    implementation("androidx.core:core-splashscreen:1.0.0")

Add this code to MainActivity.kts

        // 스플래시 스크린 딜레이 시작
        var keepSplashOnScreen = true
        val delay = 1500L
 
        installSplashScreen().setKeepOnScreenCondition { keepSplashOnScreen }
        Handler(Looper.getMainLooper()).postDelayed({ keepSplashOnScreen = false }, delay)
        // 스플래시 스크린 딜레이 끝.

themes.xml is like this