ByBit API v5 returning error code 170130: "Data sent for parameter '%s' is not valid." No explanation of what parameter '%s' is - rest

Question

I am trying to send a spot order using a unified account. There is absolutely no info about what this error message means and as far as I can tell from the ByBit v5 API docs I am doing everything correct. I have already established that the signature is formatted properly. This is the request being sent along:
RequestBuilder {
method: POST,
url: Url {
scheme: "https",
cannot_be_a_base: false,
username: "",
password: None,
host: Some(
Domain(
"api.bybit.com",
),
),
port: None,
path: "/v5/order/create",
query: None,
fragment: None,
},
headers: {
"content-type": "application/json",
"x-bapi-api-key": xxxxxxxxxxxxxx,
"x-bapi-timestamp": "1676755850417",
"x-bapi-sign": xxxxxxxxxxxxxxxx,
"x-bapi-recv-window": "5000",
},}
The request body that gets attached when the request is sent:
{"category":"spot","symbol":"ETHUSDT","side":"Sell","order_type":"Market","qty":"0.1"}
This is the Rust code used to send the request:
// Set up the HTTP client
let client = reqwest::Client::new();
let mut headers = HeaderMap::new();
headers.insert("Content-Type", HeaderValue::from_static("application/json"));
headers.insert("X-BAPI-API-KEY", HeaderValue::from_str(&api_key)?);
headers.insert("X-BAPI-TIMESTAMP", HeaderValue::from_str(&timestamp)?);
headers.insert("X-BAPI-SIGN", HeaderValue::from_str(&sign)?);
headers.insert("X-BAPI-RECV-WINDOW", HeaderValue::from_static(recv_window));
let body = serde_json::to_string(&order)?;
// Submit the order
let request = client
.post("https://api.bybit.com/v5/order/create")
.headers(headers.clone())
.body(body.clone());
let response = request.send().await?;
And this is the response received:
Response {
url: Url {
scheme: "https",
cannot_be_a_base: false,
username: "",
password: None,
host: Some(
Domain(
"api.bybit.com",
),
),
port: None,
path: "/v5/order/create",
query: None,
fragment: None,
},
status: 200,
headers: {
"content-type": "application/json; charset=utf-8",
"content-length": "122",
"x-bapi-limit": "20",
"x-bapi-limit-status": "19",
"x-bapi-limit-reset-timestamp": "1676755851552",
"ret_code": "170130",
"traceid": "78d2bec29fead6e40447a63ba1eae5d9",
"timenow": "1676755851556",
"server": "Openresty",
"expires": "Sat, 18 Feb 2023 21:30:51 GMT",
"cache-control": "max-age=0, no-cache, no-store",
"pragma": "no-cache",
"date": "Sat, 18 Feb 2023 21:30:51 GMT",
"connection": "keep-alive",
},}

Answer 1

Had to ensure that it was "orderType" and not "order_type" in the signature string and request body.