I couldn't find a good explanation of each step of signTypedData
EIP with examples of inputs and outputs at each step. I wanted this so I could keep track.
Say this is our private key
const privKey = new Buffer(
"c87509a1c067bbde78beb793e6fa76530b6382a4c0241e5e4a9ec0a0f44dc0d3",
"hex"
);