Issues with the tx_ref and the redirect_url with Flutterwave Standard

Hello,
I have an issue with the Flutterwave Standard API call. I have 2 issues with the tx_ref and redirect_url fields

Status code 400
{"status":"error","errors":[{"field":"tx_ref","message":"Transaction reference is required"},{"field":"redirect_url","message":"Redirect URL is required"}],"message":"One or more required parameters missing"}

Here the JSON

{
   "tx_ref":"ayanna-tx-001",
   "amount":"100",
   "currency":"NGN",
"redirect_url":"https://ayanna.bubbleapps.io/version-test/checkout",
   "payment_options":"card",
   "customer":{
      "email":"user@gmail.com",
      "phonenumber":"080****4528",
      "name":"Yemi Desola"
   },
   "customizations":{
      "title":"Pied Piper Payments",
      "description":"Middleout isn't free. Pay the price",
      "logo":"https://assets.piedpiper.com/logo.png"
   }
}

Do you have any ideas why I have this issue ?
Thanks for your help

Fleu

your good question and interesting information but sorry i am not idea.

Where can i find my tx reference?