curl --request POST \
  --url https://api.getsly.ai/v1/v1/mpp/sessions/{sessionId}/voucher \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "amount": 123,
  "description": "<string>",
  "request_id": "<string>"
}
'

{
  "data": {
    "id": "<string>",
    "session_id": "<string>",
    "amount": "<string>",
    "signed_voucher": "<string>",
    "created_at": "2023-11-07T05:31:56Z",
    "description": "<string>",
    "request_id": "<string>"
  },
  "budget_remaining": "<string>"
}