I'm trying to show PDF through url in webview android in java. Only Image is showing through url but not PDF

//        file_name = "07092022114344-java_tutorial.pdf";
    file_name = "07092022114344-1662530603380.jpg";
    dialog_attach_expense_info = new Dialog(MainActivity.this);
    binding.expenseAttach.setText(file_name);
    binding.expenseAttach.setOnClickListener(v -> {
        openDialogShowDownloadImagePDF();
    });

the above code is basically in the onCreate method of the main activity

private void openDialogShowDownloadImagePDF() {

    dialogBinding = DialogImagePdfBinding.inflate(getLayoutInflater());

    dialog_attach_expense_info.setContentView(dialogBinding.getRoot());
    dialog_attach_expense_info.getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    dialog_attach_expense_info.setCancelable(false);
    dialog_attach_expense_info.getWindow().getAttributes().windowAnimations = R.style.animation;
    // set background transparent
    dialog_attach_expense_info.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));

    //TODO: image view code to view image from url (PDF/Image)
    dialogBinding.webView.setWebViewClient(new WebViewClient());
    dialogBinding.webView.getSettings().setJavaScriptEnabled(true);
//        dialogBinding.webView.loadUrl("url" + file_name);
        dialogBinding.webView.loadUrl("url" + file_name);

        dialogBinding.btnCloseDialog.setOnClickListener(v -> {
            dialog_attach_expense_info.dismiss();
        });
        dialogBinding.btnDownloadDialog.setOnClickListener(v -> {
            //TODO: download event

        });

        dialog_attach_expense_info.show();
    }

Here in the above the URL is working well in chrome. But the URL that consists of .pdf is not showing up in the webview any ideas where this code lacks