EE4 Grid display customization that adds remaining spaces available for an event

grid.php

if ( $datetime instanceof EE_Datetime ) {
    $limit = $datetime->get('DTT_reg_limit');
    $remain = $datetime->spaces_remaining( true );
    if ( $datetime->sold_out() ) {
        $remaintext = '<em>Sold out</em>';
	} 
	if ( $limit == EE_INF ) {
		$remaintext = '<em>A lot available</em>';
	} else {
    	$remaintext = sprintf( _nx(
    	    '%1$sOne space available%3$s', 
    	    '%1$sThere are %2$s spaces available%3$s', 
    	    $remain, 'event ticket info', 'event_espresso' ),
    	    '<em>', $remain, '</em>'
    	);
	}
}