curl -X PUT https://console.trychert.com/api/v1/chats/ch_01H... \
  -H "x-chert-tenant: $TENANT" \
  -H "x-chert-signature: v1,$TS,$SIG" \
  -H "content-type: application/json" \
  -d '{
    "display_name": "Acme launch crew",
    "group_chat_icon": "https://cdn.example.com/acme-icon.png"
  }'

const ts = Math.floor(Date.now() / 1000)
const body = JSON.stringify({
  display_name: "Acme launch crew",
  group_chat_icon: "https://cdn.example.com/acme-icon.png",
})
const sig = crypto.createHmac("sha256", SIGNING_SECRET).update(`${ts}.${body}`).digest("hex")
const res = await fetch(`https://console.trychert.com/api/v1/chats/${chatId}`, {
  method: "PUT",
  headers: {
    "Content-Type": "application/json",
    "x-chert-tenant": TENANT_SLUG,
    "x-chert-signature": `v1,${ts},${sig}`,
  },
  body,
})

import hmac, hashlib, json, time, requests
ts = int(time.time())
body = json.dumps({
    "display_name": "Acme launch crew",
    "group_chat_icon": "https://cdn.example.com/acme-icon.png",
})
sig = hmac.new(SIGNING_SECRET.encode(), f"{ts}.{body}".encode(), hashlib.sha256).hexdigest()
r = requests.put(
    f"https://console.trychert.com/api/v1/chats/{chat_id}",
    headers={
        "Content-Type": "application/json",
        "x-chert-tenant": TENANT_SLUG,
        "x-chert-signature": f"v1,{ts},{sig}",
    },
    data=body,
)

{
  "chat": {
    "id": "ch_01H...",
    "display_name": "Acme launch crew",
    "group_chat_icon": "https://cdn.example.com/acme-icon.png",
    "is_group": true
  }
}