Create an event post with PHP

I am creating an event as such:

$newEvent = array(
‘post_type’ => ‘event_listing’,
‘post_title’ =>$title,
‘post_status’ => ‘publish’,
‘meta_input’=> array(
‘_event_title’ =>$title,
‘_event_category’ => $categories,
‘_event_start_date’ => $startDate,
‘_event_end_date’ => $endDate,
‘_event_banner’ => $image,
‘_links_to’ => $url,
‘_event_location’ => $venue
)

I am struggling to set the event category. How do I do so?