How to define Key to create dataset using C#? What is the input value of Key?

Key is a unique value in the map. You can create your own with following constraints:

  1. Key Length: Minimum length of 1. Maximum length of 64.
  2. Key Pattern: [0-9a-zA-Z-]*

For more information, please see https://docs.aws.amazon.com/quicksight/latest/APIReference/API_CreateDataSet.html#QS-CreateDataSet-request-PhysicalTableMap