curl --request POST \
  --url https://api.neynar.com/v2/farcaster/block/ \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
  "signer_uuid": "19d0c5fd-9b33-4a48-a0e2-bc7b0555baec",
  "blocked_fid": 3
}'

{
  "success": true,
  "message": "<string>"
}