curl --request POST \
  --url https://api.mudstack.com/workspaces/assets/{asset_id}/attachments/{attachment_id}/thumbnail \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --header 'x-account-id: <x-account-id>' \
  --header 'x-workspace-id: <x-workspace-id>'

{
  "id": "<string>",
  "asset_id": "<string>",
  "created_by_user_id": "<string>",
  "file_id": "<string>",
  "thumbnail_file_id": "<string>",
  "review_id": "<string>",
  "comment_id": "<string>",
  "name": "<string>",
  "description": "<string>",
  "user": {
    "id": "<string>",
    "auth0UserID": "<string>",
    "username": "<string>",
    "email": "<string>",
    "firstName": "<string>",
    "lastName": "<string>",
    "avatar_file_id": "<string>",
    "defaultAvatar": 123,
    "industry": "<string>",
    "occupation": "<string>",
    "company": "<string>",
    "emailVerified": true,
    "isActive": true,
    "city": "<string>",
    "state": "<string>",
    "country": "<string>",
    "zipCode": "<string>",
    "invited_by_user": {}
  }
}