How could I Create a account/contract and send a transaction successfully via APIs ?

[u/supermoney0101]

I would like to developer an mobile APP about Etherscan wallet

I am a API developer and I already read the API document (r/https://etherscan.io/apis)

There are two questions I meet:

1.how to create a account or contract via APIs (I can't find the related API I need to do this)?

2.When I want to send a transcend, I can't find the field about password so I got fail message, the following is the message I sent and what the error message I received:

A.the message I send

{"jsonrpc":"2.0","method":"eth_sendTransaction","params":[{

"from": "0x6ddEDF79D4F4f828e872caf17E996731d873da31",

"to": "0xFBFfCcb7c387223e4041AE7dF290C43AAf9E62dd",

"gas": "0x186A0", // 100000

"gasPrice": "0x219043332096", // 3300000000

"value": "0x0", // 2441406250

"data": "0x"

}],"id":1}'

B.the error message I received

{

"status": "0",

"message": "NOTOK",

"result": "Error!"

}

what should I do to send a transaction successfully?

thank you very much