curl --request POST \
  --url https://api.neynar.com/v2/farcaster/signer/ \
  --header 'x-api-key: <api-key>'

{
  "object": "signer",
  "signer_uuid": "19d0c5fd-9b33-4a48-a0e2-bc7b0555baec",
  "public_key": "0x3daa8f99c5f760688a3c9f95716ed93dee5ed5d7722d776b7c4deac957755f22",
  "status": "generated",
  "signer_approval_url": "<string>",
  "fid": 3,
  "permissions": [
    "WRITE_ALL"
  ]
}