Customize taxonomy term before it is indexed by SearchWP

searchwp-customizations.php

<?php

// Customize taxonomy term before it is indexed by SearchWP.
add_filter( 'searchwp\source\post\attributes\taxonomy\term', function( $term, $args ) {
  // Add 'coffee' to specific term name so it is searchable.
  if ( 'My Custom Term' === $term->name ) {
    $term->name .= ' coffee';
  }

  return $term;
}, 20, 2 );