Hear about denied PayPal payments

from clickruntime import on_event, credentials, http, notify

API = "https://api-m.paypal.com"

def paypal_headers():
    resp = http.post(f"{API}/v1/oauth2/token", data={"grant_type": "client_credentials"},
                     auth=(credentials.secret("PAYPAL_CLIENT_ID"), credentials.secret("PAYPAL_CLIENT_SECRET")))
    resp.raise_for_status()
    return {"Authorization": f"Bearer {resp.json()['access_token']}"}

@on_event
def handle(event):
    body = event.json
    if body.get("event_type") != "PAYMENT.CAPTURE.DENIED":
        return {"posted": False}
    capture = body["resource"]
    order_id = capture.get("supplementary_data", {}).get("related_ids", {}).get("order_id")
    payer = "unknown payer"
    if order_id:
        p = http.get(f"{API}/v2/checkout/orders/{order_id}", headers=paypal_headers()).json()["payer"]
        payer = f"{p['name']['given_name']} {p['name']['surname']} ({p['email_address']})"
    amount = capture["amount"]
    notify.slack(f"❌ PayPal payment denied: {payer}, {amount['currency_code']} {amount['value']}\n"
                 f"Transaction: {capture['id']}", channel="#payments")
    return {"capture": capture["id"]}