If you’re using the Back To Parent broadcast plugin and want the checkbox always selected, you’ll have to use some javascript.
Below is a whole plugin that you can put in your plugins directory. Activate it and the checkbox will be automatically selected.
<?php
/*
Author: edward_plainview
Author Email: edward@plainviewplugins.com
Author URI: https://broadcast.plainviewplugins.com
Description: Selects the Back To Parent checkbox
Plugin Name: B2P Select
Plugin URI: https://broadcast.plainviewplugins.com/threewp-broadcast/
Version: 1
*/
add_action( 'admin_footer', 'b2p_checkbox' );
function b2p_checkbox()
{
echo '<script type="text/javascript">
jQuery( document ).ready( function($ )
{
$( "#plainview_sdk_broadcast_form2_inputs_checkbox_back_to_parent" ).attr( "checked", "checked" );
} );
</script>';
}