curl --request POST \
  --url https://api.example.com/blockchain/verify-location \
  --header 'Content-Type: application/json' \
  --data '
{
  "drone_id": "<string>",
  "location": {
    "latitude": 123,
    "longitude": 123,
    "altitude": 123
  },
  "timestamp": 123
}
'

{
  "is_valid": true,
  "attestation_tx": "<string>",
  "confidence": 123
}