Create Sender

curl --request POST \
  --url https://api.sendx.io/api/v1/rest/sender \
  --header 'Content-Type: application/json' \
  --header 'X-Team-ApiKey: <api-key>' \
  --data '{
  "name": "Linus",
  "email": "linus@linux.org"
}'

{
  "id": "sender_123",
  "name": "Linus",
  "email": "linus@linux.org"
}