How to use `get_ipython().payload_manager.write_payload` create markdown cell?

I want to programmatically create several markdown cells in a Jupyter notebook.

the following function works for code cells, but not markdown cells.

def create_new_cell(contents):
    from IPython.core.getipython import get_ipython
    shell = get_ipython()

    payload = {
        "source": "set_next_input",
        "text": contents,
        "replace": False
    }
    shell.payload_manager.write_payload(payload, single=False)

I try to add metadata setting, but it doesn't work.

def create_new_cell(contents):
    from IPython.core.getipython import get_ipython
    shell = get_ipython()

    payload = {
        "source": "set_next_input",
        "text": contents,
        "metadata": {"cell_type": "markdown"},
        "replace": False
    }
    shell.payload_manager.write_payload(payload, single=False)

Is there any other solution?