How to use the cellbrowser.cellbrowser.serve function in cellbrowser

adata,
        data_dir,
        data_name,
        coordFields=embedding_keys,
        metaFields=annot_keys,
        clusterField=cluster_field,
        nb_marker=nb_marker,
        skipMatrix=skip_matrix,
        doDebug=None,
    )

    if html_dir is not None:
        html_dir = str(html_dir)
        cb.build(data_dir, html_dir, doDebug=None)
        if port is not None:
            cb.serve(html_dir, port)