Sending request to reCAPTCHA Enterprise API fails

I am trying to create ReCaptcha assessment using their REST API in my backend server.

From reading the documentation, I understand that the request body contains an instance of Assesment, but when I try to send a request, I receive the following error:

TypeError: Object of type Assessment is not JSON serializable

My code:

import requests
from google.cloud import recaptchaenterprise_v1
from google.cloud.recaptchaenterprise_v1 import Assessment

def create_assessment(project_id: str, recaptcha_site_key: str, token: str, recaptcha_action: str, apiKey:str):

    # Create event object
    event = recaptchaenterprise_v1.Event()
    event.site_key = recaptcha_site_key
    event.token = token

    # Create assesment object
    assessment = recaptchaenterprise_v1.Assessment()
    assessment.event = event
    
    # Set project name
    project_name = "projects/"+project_id

    response = requests.post(url="https://recaptchaenterprise.googleapis.com/v1/"+project_name+"/assessments?key="+apiKey, json=assessment)

    return response

I tried to convert the assesment to JSON using dumps(), but I had no success.

I've also tried to write it as "skinny JSON" like so:

assessment = {
    'event': {
        'token': token,
        'siteKey': recaptcha_site_key,
        'expectedAction': 'LOGIN'
    }
}

Even though I receive status code 200, it indicates that my request is MALFORMED, probably because I don't include some recaptchaenterprise_v1 objects that should be on the assesment.

Try to use the CreateAssessmentRequest to create the request instead, like so:

client = recaptchaenterprise_v1.RecaptchaEnterpriseServiceClient()
project_name = "projects/"+project_id

# Build the assessment request.
request = recaptchaenterprise_v1.CreateAssessmentRequest()
request.assessment = assessment
request.parent = project_name

response = client.create_assessment(request)

You can find a more complete code sample in GCP's documentation.