curl --request POST \
  --url https://api.xplenty.com/{account_id}/api/members \
  --header 'Accept: <accept>' \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "email": "jsmith@example.com"
}
'

{
  "id": 123,
  "display_name": "<string>",
  "email": "jsmith@example.com",
  "created_at": "2023-11-07T05:31:56Z",
  "updated_at": "2023-11-07T05:31:56Z",
  "avatar_url": "<string>",
  "url": "<string>",
  "html_url": "<string>"
}