How to Hide the "SUMIT" Dashboard Widget

function plt_hide_woo_payment_gateway_officeguy_dashboard_widgets() {
	$screen = get_current_screen();
	if ( !$screen ) {
		return;
	}

	//Remove the "SUMIT" widget.
	remove_meta_box('officeguy_dashboard_widget', 'dashboard', 'normal');
}

add_action('wp_dashboard_setup', 'plt_hide_woo_payment_gateway_officeguy_dashboard_widgets', 20);

Where do I put this code?