/* Force WordPress to output optimized WebP images by default on upload */
add_filter( 'image_editor_output_format', function( $formats ) {
    $formats['image/jpeg'] = 'image/webp';
    $formats['image/png']  = 'image/webp';
    return $formats;
} );

/* Set WebP Compression Quality to 80% (Optimal speed/quality balance) */
add_filter( 'wp_editor_set_quality', function( $quality, $mime_type ) {
    if ( 'image/webp' === $mime_type ) {
        return 80;
    }
    return $quality;
}, 10, 2 );
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://koperry.com/wp-sitemap-index.xsl" ?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><sitemap><loc>https://koperry.com/wp-sitemap-posts-page-1.xml</loc></sitemap></sitemapindex>