Create Origin Cert via API -- do I need a CSR? Seems like I shouldn't.

CF_API_BASE = "https://api.cloudflare.com/client/v4"

load_dotenv()
ORIGIN_CA_KEY = os.getenv("ORIGIN_CA_KEY")

def get_headers(origin_ca_key):
    return {
        "X-Auth-User-Service-Key": origin_ca_key,
        "Content-Type": "application/json",
    }

def issue_origin_ca_cert(origin_ca_key, domains):
    url = f"{CF_API_BASE}/certificates"
    payload = {
        "hostnames": domains,
        "requested_validity": 5475,
        "request_type": "origin-rsa"
    }
    resp = requests.post(url, json=payload, headers=get_headers(origin_ca_key))
    if resp.status_code != 200:
        print(f"[ERROR] Cloudflare API error (issue origin ca cert): {resp.text}")
        return None, None, None
    result = resp.json()["result"]
    return result["certificate"], result["private_key"], result.get("id", "new")

[INFO] Starting process for 1 domain(s).
[ACTION] Issuing new origin ca cert for redacated.com and *.redacated.com...
[ERROR] Cloudflare API error (issue origin ca cert): {"success":false,"messages":[],"errors":[{"code":1007,"message":"CSR parsed as empty"}],"result":{},"result_info":{"count":0,"total_count":0}}
[ERROR] Could not create or save new origin ca cert for redacated.com.
[INFO] Done.