The address type, right now, only "evm" is supported
No, default is "evm"
Example Responses
{"code":0,"data":{"items":[{"sign_key":"0x1867998e827d10d4482e3f49d8ac68c17f29f9588c9b04e84ea2e3059e1f9958","statement":"I am declaring to use the key \"0x1867998e827d10d4482e3f49d8ac68c17f29f9588c9b04e84ea2e3059e1f9958\" as my signing key of engagement data for \"0x7e031555600E59f37dDE3Bb9C5D8205c61796a0D\".","timestamp":1652882537,},]},"message":"success"}