Check VAT numbers on Stripe invoices and email the right person

import base64
from email.message import EmailMessage
from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
import stripe
from clickruntime import on_event, credentials, verify, http

def send(to, subject, text):
    msg = EmailMessage(); msg["To"], msg["Subject"] = to, subject; msg.set_content(text)
    g = build("gmail", "v1", credentials=Credentials(credentials.connection("google", "work")), cache_discovery=False)
    g.users().messages().send(userId="me", body={"raw": base64.urlsafe_b64encode(msg.as_bytes()).decode()}).execute()

@on_event
def handle(event):
    if not verify.stripe(event.body, event.header("Stripe-Signature"), credentials.secret("STRIPE_WEBHOOK_SECRET")):
        return {"ignored": "bad signature"}
    inv = event.json["data"]["object"]
    if event.json["type"] == "invoice.finalized":
        send(inv["customer_email"], f"Invoice {inv['number']}", f"Hello,\n\nYour invoice is ready: {inv['hosted_invoice_url']}\n\nThank you.")
        return {"sent": "customer"}
    stripe.api_key = credentials.secret("STRIPE_API_KEY")
    vat = next((t for t in stripe.Customer.list_tax_ids(inv["customer"]).data if t.type == "eu_vat"), None)
    if not vat:
        return {"vat": None}
    r = http.post("https://ec.europa.eu/taxation_customs/vies/rest-api/check-vat-number", json={"countryCode": vat.value[:2], "vatNumber": vat.value[2:]})
    if r.status_code != 200 or not r.json().get("valid"):
        send("finance@example.com", f"VAT check failed: {inv.get('customer_name')}", f"VAT number {vat.value} did not validate for draft invoice {inv['id']}.")
    return {"vat": vat.value, "status": r.status_code}