If you are not a WordPress developer you could consider to use the "Advanced Custom Fields" plugin:
https://nl.wordpress.org/plugins/advanced-custom-fields/
If you are familiair with WordPress hooks you can also use the pronamic_event_fields
filter from the Pronamic Events plugin:
https://github.com/pronamic/wp-pronamic-events/blob/1.2.1/admin/meta-box-event-details.php#L59-L87
You could for example add the following code/function to a custom plugin or your custom theme functions.php file:
<?php
function my_pronamic_event_fields( $fields ) { $fields['organiser'] = array( 'id' => 'pronamic_event_organiser', 'label' => __( 'Organiser', 'my-text-domain' ), 'meta_key' => '_pronamic_event_organiser', ); return $fields;
}
add_filter( 'pronamic_event_fields', 'my_pronamic_event_fields' );