can't upload webp to wordpress
function webp_upload_mimes( $existing_mimes ) {
// add webp to the list of mime types
$existing_mimes['webp'] = 'image/webp';
// return the array back to the function with our added mime type
return $existing_mimes;
}
add_filter( 'mime_types', 'webp_upload_mimes' );