Errors when using custom taxonomy

Hi,
Looking at using this – but when using a Custom Taxonomy linked to a CPT, but get a fatal error in this file…

/Users/neilg/Sites/fsa/wp-content/plugins/media-recode-custom-modules/mr-multipoint-map/includes/frontend.js.php on line 53

which is this code…
$category = get_the_terms(get_the_ID(), $settings->post_taxonomy)[0];