curl --request POST \
  --url https://app.getcensus.com/api/v1/sources/{source_id}/topics \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "name": "NewAppUsers",
  "sample_message": {
    "name": "Jill",
    "id": "1",
    "email": "Jill@foo.com"
  },
  "description": "Users that have signed up for our product in the last week."
}'

{
  "status": "created",
  "data": {
    "id": 18,
    "name": "NewAppUsers",
    "description": "Users that have signed up for our product in the last week.",
    "created_at": "2021-10-20T02:43:07.120Z",
    "updated_at": "2021-10-20T02:50:35.477Z",
    "schema": {
      "name": "string",
      "id": "number",
      "email": "string"
    }
  }
}