CURL

Please specify base64 encoding, Solana recognizes base58 as default. If you do not specify, you might get malformed transaction error

curl <url> -X POST -H "Content-Type: application/json" -d '                                   
  {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "sendTransaction",
    "params": [      "<base64_tx_data>",
      {                                                                                
        "encoding": "base64",
      }
    ]
  }