This is my javascript function-

function backHomePage(message){window.webkit.messageHandlers.backHomePage.postMessage(message);}

in end it is called as- backHomePage('popup');

Now in my Android app I want to add this javascript function in my JavascriptInterface.

I have done following approach-

override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
        
            super.onPageStarted(view, url, favicon)
            webview_.evaluateJavascript("window.webkit = { messageHandlers: { backHomePage: window.backHomePage('popup')} }") {}

        }

webview_.addJavascriptInterface(WebAppInterface(this),"backHomePage")
webview_.loadUrl(url)

and my WebAppInterface class is like this-

class WebAppInterface(private var mContext: Context) {

fun WebAppInterface(c: Context) {
    mContext = c
}

@JavascriptInterface
fun postMessage() {
    Log.d("tag", "postMessage message")
}

Now am not getting in which thing I'm lagging, As I have done everything at my understanding. Can anyone please help?