Query order by custom field

I am following the instructions here : https://docs.generateblocks.com/article/order-query-loop-by-custom-field/
But can’t seem to get ordering by an ACF field working.

Here is my code:

add_filter( ‘generateblocks_query_loop_args’, function( $query_args, $attributes ) {
// apply filter if loop has class: my-class-name
if (
! empty( $attributes[‘className’] ) &&
strpos( $attributes[‘className’], ‘in-date-order’ ) !== false
) {
// merge meta_key my-custom-field into query
return array_merge( $query_args, array(
‘meta_key’ => ‘event_date’,
‘orderby’ => ‘meta_value’,
‘meta_type’ => ‘DATE’,
‘order’ => ‘ASC’,
) );
}

return $query_args;

}, 10, 2 );

I am using an ACF datepicker field.