Index taxonomy term metadata alongside taxonomy term in SearchWP

functions.php

<?php

// Index taxonomy term metadata alongside taxonomy term in SearchWP.
add_filter( 'searchwp_indexer_taxonomy_term', function( $to_index, $context ) {
	$term_meta = get_term_meta( $context['term']->term_id, 'my_term_meta_key', true );

	// If the metadata exists, append it to the string to be indexed by SearchWP.
	return ! empty( $term_meta ) ? $to_index . ' ' . $term_meta : $to_index;
}, 10, 2 );