curl --request GET \
  --url https://saas.pads365.com/rdx/NDS.Services.Viewer/api/v1/Viewer/ViewerVariables

{
  "Succeeded": true,
  "Message": "<string>",
  "Code": "<string>",
  "Variables": [
    {
      "Id": "<string>",
      "Name": "<string>",
      "Description": "<string>",
      "DefaultValue": "<string>"
    }
  ],
  "Values": [
    {
      "Id": "<string>",
      "VariableId": "<string>",
      "DestinationId": "<string>",
      "Value": "<string>"
    }
  ]
}