taxonomy_by_search_keyword.php

if( !function_exists( 'load_terms_by_ajax' ) ) {
    function load_terms_by_ajax(){
        $ky = isset( $_GET['q'] ) && !empty( $_GET['q'] ) ? $_GET['q'] : '';
        $term_name =  isset( $_GET['key'] ) && !empty( $_GET['key'] ) ? $_GET['key'] : '';
        $texonomy_sarch_args = array('hide_empty' => true,'orderby' => 'name','order' => 'ASC', 'name__like' => $ky, );
        $tax_obj = get_terms( $term_name, $texonomy_sarch_args );
        $arr['results'] = array();
        if( count( $tax_obj ) > 0 ){

            foreach( $tax_obj as $item ){
                $arr['results'][] = array(
                    'id' => $item->term_id,
                    'text' => $item->name,
                );
            }
        }
        echo json_encode($arr);

        die();
    }
}
add_action( 'wp_ajax_load_terms_by_ajax', 'load_terms_by_ajax' );
add_action( 'wp_ajax_nopriv_load_terms_by_ajax', 'load_terms_by_ajax' );