Create Variant

curl --request POST \
  --url https://try.flipt.io/api/v1/namespaces/default/flags/{flagKey}/variants \
  --header 'Content-Type: application/json' \
  --header 'Accept: application/json' \
  --data '{
  "key": "<key>",
  "name": "<name>",
  "description": "<description>",
  "attachment": "<attachment>"
}'

{
  "id": "<string>",
  "flagKey": "<string>",
  "key": "<string>",
  "name": "<string>",
  "description": "<string>",
  "createdAt": "2023-11-07T05:31:56Z",
  "updatedAt": "2023-11-07T05:31:56Z",
  "attachment": "<string>",
  "namespaceKey": "<string>"
}