Allowed Origin function python 3.9

def main(context):
    """
    This function is called as an api.
    """

    response = {
        'message': 'Hello World!',
        'api': 'default',
    }

    if context.req.path == '/v1/list':
        data = list_domain()
        response['api'] = 'list'
        response['data'] = data
        headers = {
            'Access-Control-Allow-Origin': os.environ['ALLOW_ORIGIN']
        }
        context.log(headers)
        return context.res.json(response, headers=headers)

    if context.req.path == '/v1/search':
        query_param = context.req.query
        domain = query_param['domain']
        data = search_domain(domain)
        response['api'] = 'search domain'
        response['data'] = data
        headers = {
            'Access-Control-Allow-Origin': os.environ['ALLOW_ORIGIN']
        }
        return context.res.json(response, headers=headers)

    return context.res.empty()