Error 429 is:
{
"code": 7638,
"message": "There is another request in flight trying to perform the same action."
}
Error 529 is:
{
"code": 7746,
"message": "This fetch token is currently being ingested. Please retry the request again to ensure any changes since the initial request are ingested."
}
This can happen if we do multiple `POST /receipts` for the same user.
Do they have a different meaning? Is there a nuance in how we should handle these?