curl --request POST \
  --url https://arch-mainnet.gomaestro-api.org/v0/rpc/transaction/send \
  --header 'Content-Type: application/json' \
  --header 'api-key: <api-key>' \
  --data '{
  "message": {
    "instructions": [
      {
        "accounts": [
          {
            "is_signer": true,
            "is_writable": true,
            "pubkey": [
              123
            ]
          }
        ],
        "data": [
          123
        ],
        "program_id": [
          123
        ]
      }
    ],
    "signers": [
      [
        123
      ]
    ]
  },
  "signatures": [
    [
      123
    ]
  ],
  "version": 123
}'

{
  "data": "<string>",
  "last_updated": {
    "block_hash": "<string>",
    "block_height": 123
  }
}