HTML不会将参数传递给缺少1个必需的位置参数的烧瓶

{% block content %}
<div class="row">
    {% if chirp %}

    <h2>{{ chirp[1] }}</h2>
    <p>
        By : {{ chirp[2] }}
    </p>
    <p>
        {{ chirp[3] }}
    </p>
       
    <div>
        <a class="btn btn-success" href="{{ url_for('createCmt', chirp_id='{{ chirp[0] }}') }}"> + Comment </a>
    </div>

    {% else %}
    <h3>
        Invalid comment
    </h3>
    {% endif %}
</div>

@app.route('/comment/create', methods=['GET', 'POST'])
def createCmt(chirp_id):
    # check if user is logged in
    if not session:
        return redirect(url_for('login'))

    if request.method == 'POST':
        data = request.get_json() or {}
        if data.get('body'):
            user_id = session.get('user_id')
            body = data.get('body', '')            

            body = body.strip()
            sql_params = (chirp_id, user_id, body)

            conn = db_connection()
            cur = conn.cursor()
            sql = """
                INSERT INTO commentary (chirp_id, user_id, body) VALUES (%d, %d, '%s')
            """ % sql_params
            cur.execute(sql)
            conn.commit()
            cur.close()
            conn.close()
            return jsonify({'status': 200, 'message': 'Success', 'redirect': '/'})

        return jsonify({'status': 500, 'message': 'No Data submitted'})

    return render_template('comment/create.html')

{% extends "comment/form.html" %}

{% block title %}
Create a Comment
{% endblock %}

{% block button %}
<div class="row">
    <div class="offset-2 col-6">
        <button type="button" class="btn btn-success" name="btnCreate" id="btnCreate" onclick="createCUM()">Create</button>
    </div>
</div>
{% endblock %}

function createCUM(chirp_id) {
    var body = document.getElementById("body").value;

    axios({
        method: "POST",
        url: "/comment/create/" + chirp_id,
        data: {
            body: body,
        },
        headers: {
            "Content-Type": "application/json",
        }
    }).then(
        (response) => {
            var data = response.data;
            if (data.redirect) {
                // redirect exists, then set the URL to the redirect
                window.location.href = data.redirect;
            }

            if (data.status == 500) {
                alert(data.error);
                window.location.href = "/";  // redirect to home page
            }
        },
    )
}