How to read the state of an HTML checkbox in Python / flask

The checkbox exists in the browser, the python code runs on the server. Basically the server will have no knowlegde of the checkbox state. If you want to change that, you need to connect the two.

Two options there:

(1): the checkbox is included in a form and the state is included in the form data when the user clicks submit.

(2): you assign an event handler to the state of the checkbox. On the event handler, you post the new state to some AJAX resource. In Flask you add a route for the AJAX URL and receive the state changes.

Here is what I am trying to do. I added a action (form action) line in html, then a function in python to process it. But the python function never executes so I clearly don't have something right.

here is the html:

<td style="width:auto">
<form action="ManToggle">
<div class="slideThree">
    <input type="checkbox" value="None" id="chk_01_Man" name="chk_01_Man" />
    <label for="chk_01_Man"></label>
</div>
</form>
</td> 

Here is the python:

@app.route('/ManToggle', methods=['GET'])
def ManToggleUpdate():
    print ("function executes")
    test = request.form['chk_01_Man']
    if test == True :
        # do something
    else :
        # do something else