One API. More possibilities.

# Server environment: OMINI_BASE_URL=https://YOUR_OMINI_HOST/api/v1
# Keep OMINI_API_KEY in your server's secret manager.
# Save one UUID with your business event before its first attempt.
cat > message.json <<'JSON'
{
  "sender_id": "YOUR_APPROVED_SENDER_UUID",
  "to": "+233241234567",
  "body": "Your delivery is on its way.",
  "idempotency_key": "PERSISTED_UUID_FOR_THIS_MESSAGE"
}
JSON
# Replace placeholders in message.json; keep identical content on retry.
curl --fail-with-body --include --max-time 30 \
  "$OMINI_BASE_URL/sms/messages" \
  -H "Authorization: Bearer $OMINI_API_KEY" \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  --data-binary @message.json

// Server-side JavaScript (Node.js 18+), not a browser bundle.
const base = process.env.OMINI_BASE_URL.replace(/\/$/, '');
const payload = {
  sender_id: process.env.OMINI_SENDER_ID,
  to: '+233241234567',
  body: 'Your delivery is on its way.',
  idempotency_key: process.env.OMINI_MESSAGE_UUID // persist before first attempt
};
const response = await fetch(`${base}/sms/messages`, {
  method: 'POST',
  signal: AbortSignal.timeout(30000),
  headers: {
    Authorization: `Bearer ${process.env.OMINI_API_KEY}`,
    Accept: 'application/json', 'Content-Type': 'application/json'
  },
  body: JSON.stringify(payload)
});
const supportRequestId = response.headers.get('X-Request-Id');
if (response.status !== 202) {
  throw new Error(`Omini HTTP ${response.status}; request ${supportRequestId}`);
}
const accepted = await response.json();
// Persist accepted.data.id (message ID) and accepted.data.request_id (job ID).
// GET /sms/messages/{message ID} to check delivery; 202 is not delivery.

# Python 3.10+, standard library only. Run on your server.
import json
import os
import urllib.error
import urllib.request

payload = {
    "sender_id": os.environ["OMINI_SENDER_ID"],
    "to": "+233241234567",
    "body": "Your delivery is on its way.",
    "idempotency_key": os.environ["OMINI_MESSAGE_UUID"]  # persisted UUID
}
request = urllib.request.Request(
    os.environ["OMINI_BASE_URL"].rstrip("/") + "/sms/messages",
    data=json.dumps(payload).encode("utf-8"),
    headers={"Authorization": "Bearer " + os.environ["OMINI_API_KEY"],
             "Accept": "application/json", "Content-Type": "application/json"},
    method="POST"
)
try:
    with urllib.request.urlopen(request, timeout=30) as response:
        if response.status != 202:
            raise RuntimeError("Unexpected Omini response")
        accepted = json.load(response)
        message_id = accepted["data"]["id"]  # persist; poll delivery separately
except urllib.error.HTTPError as error:
    raise RuntimeError(
        f"Omini HTTP {error.code}; request {error.headers.get('X-Request-Id')}"
    ) from None
# On timeout or 5xx, check the job or retry identical content with the SAME UUID.