The required parameters depend on the transaction type. Check the proper parameters in Klaytn Docs.
// Request
curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0", "method":"klay_signTransaction", "params":[{"from":"0x77982323172e5b6182539d3522d5a33a944206d4", "to":"0xcd6bfdb523a4d030890d28bf1eb6ef36307c9aaa", "value":"0x10000", "gas":"0x1000000", "nonce":"0x2", "gasprice":"0x25000000000"}],"id":73}' http://klaytn.blockpi.network/v1/rpc/your-api-key
// Result
{
"jsonrpc":"2.0",
"id":73,
"result":{
"raw":"0xf86c0286025000000000840100000094cd6bfdb523a4d030890d28bf1eb6ef36307c9aaa8301000080820fe8a056d2ddd231c3c111687ab351d339240db18cd721e5aa33c601dd4fc3927fb4d1a03443443392517aa7da082aa0a00b9ee5e3e1ee007d22e57cd9ff55b5ddbf4a64",
"tx":{
"nonce":"0x2",
"gasPrice":"0x5d21dba00",
"gas":"0x1000000",
"to":"0xcd6bfdb523a4d030890d28bf1eb6ef36307c9aaa",
"value":"0x10000",
"input":"0x",
"v":"0xfe8",
"r":"0x56d2ddd231c3c111687ab351d339240db18cd721e5aa33c601dd4fc3927fb4d1",
"s":"0x3443443392517aa7da082aa0a00b9ee5e3e1ee007d22e57cd9ff55b5ddbf4a64",
"hash":"0xb53cc9128a19c3916c0de1914725b7337bba84666c2556d8682c72ca34c6874c"
}
}
}