Add custom file type in wp (i.e: webP)

//** *Enable upload for webp image files.*/
function webp_upload_mimes($existing_mimes) {
    $existing_mimes['webp'] = 'image/webp';
    return $existing_mimes;
}
add_filter('mime_types', 'webp_upload_mimes');

//** * Enable preview for webp image files.*/
function webp_is_displayable($result, $path) {
    if ($result === false) {
    $displayable_image_types = array( IMAGETYPE_WEBP );
    $info = @getimagesize( $path );

if (empty($info)) {
    $result = false;
} elseif (!in_array($info[2], $displayable_image_types)) {
    $result = false;
} else {
    $result = true;
}
}
return $result;

}
add_filter('file_is_displayable_image', 'webp_is_displayable', 10, 2);