This was almost right
<?php
$queried_object = get_queried_object();
$taxonomy = $queried_object->taxonomy;
$term_id = $queried_object->term_id;
$value = get_field( 'test_field', $taxonomy.'_'.$term_id);
if( $value ) {
echo $value;
} else {
echo 'empty';
}
?>