Permission to hit google API from a cloud function?

I need to get the Airflow URL and other information from Composer. For that I'm trying to use the Google API (https://composer.googleapis.com/v1beta1/projects/PROJECT_ID/locations/COMPOSER_LOCATION/environments/COMPOSER_NAME'). This is the code that I use:

import logging
import requests

import google.cloud.logging
from google.auth.transport.requests import AuthorizedSession

client = google.cloud.logging.Client(project="project ID of the Cloud Function")
client.setup_logging()

AUTH_SCOPE = "https://www.googleapis.com/auth/cloud-platform"
CREDENTIALS, _ = google.auth.default(scopes=[AUTH_SCOPE])


def request_api(url: str, method: str) -> dict:
    authed_session = AuthorizedSession(CREDENTIALS)
    response = authed_session.request(method, url)

    if response.status_code == 403:
        raise requests.HTTPError(
            "You do not have a permission to perform this operation. "
            "Check Airflow RBAC roles for your account."
            f"{response.headers} / {response.text}"
        )
    elif response.status_code != 200:
        response.raise_for_status()
    else:
        return response.json()


def main():
    project_id = 'some project ID'
    location = 'some location'
    composer_name = 'some composer name'
    request_url = (
        'https://composer.googleapis.com/v1beta1/'
        f'projects/{project_id}/'
        f'locations/{location}/'
        f'environments/{composer_name}'
    )

    response = request_api(request_url, 'GET')
    logging.info(f"Response from API: {response}")

But when I run it I got an HTTP 403 error.

{ "error": { "code": 403, "message": "The caller does not have permission", "status": "PERMISSION_DENIED" } }

In this case the caller is the service account that run the Cloud Function, right? So what permissions must have the service account that run the cloud function?

Thanks in advance.

According to Puteri comment. My cloud function can consume the Composer API if their service account have the role Composer User (roles/composer.user).