Click button automatically in webview?

I created an app with Webview and need to press button automatically

Use case:- open link web link and want to press "Login Here" button automatically (Second button at right).

I tried Using this:-

Html from website for "Login Here" button was <input _ngcontent-c13="" style="padding: 2px" type="button" class="pri_btn" value="Login Here"> It does not have id or name so i tried with class name but nothing happened

String js = "javascript:(function(){"+
    "l=document.getElementByClassName('pri_btn');"+
    "e=document.createEvent('HTMLEvents');"+
    "e.initEvent('click',true,true);"+
    "l.dispatchEvent(e);"+
    "})()";
    webView.evaluateJavascript(js, new ValueCallback<String>() {
        @Override
        public void onReceiveValue(String s) {
            String result = s;

        }
    });

which return null.

Any help will be appreciated!

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