固定ページ　拡張子をhtmlに

functions.php

add_action( ‘init’, ‘mytheme_init’ );
if ( ! function_exists( ‘mytheme_init’ ) ) {
function mytheme_init() {
global $wp_rewrite;
$wp_rewrite->use_trailing_slashes = false;
$wp_rewrite->page_structure = $wp_rewrite->root . ‘%pagename%.html’;
// flush_rewrite_rules( false );
}
}