Initiate payment session

curl --request POST \
  --url https://admin.aeoliancms.com/api/v1/payments/initiate \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "items": [
    {
      "variantId": "<string>",
      "quantity": 2
    }
  ],
  "currency": "<string>"
}
'

{
  "processor": "stripe",
  "sessionId": "<string>",
  "publishableKey": "<string>",
  "amount": 123,
  "currency": "<string>",
  "breakdown": {
    "subtotal": 123,
    "shipping": 123,
    "tax": 123,
    "total": 123
  }
}