TI Map Domain entity to Cloud App Events

let dt_lookBack = 1h;
let ioc_lookBack = 14d; 
let list_tlds =
  ThreatIntelIndicators
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
| where IsActive and (ValidUntil > now() or isempty(ValidUntil))
    //extract key part of kv pair
| extend IndicatorType = replace(@"\[
| \]
| \""", "", tostring(split(ObservableKey, ":", 0)))
| where IndicatorType == "domain-name"
| extend DomainName = tolower(IndicatorType)
| extend parts = split(DomainName, '.')
| extend tld = parts[(array_length(parts) - 1)]
| extend IndicatorId = tostring(split(Id, "--")[2])
| summarize count() by tostring(tld)
| summarize make_set(tld);
let Domain_Indicators =
  ThreatIntelIndicators
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
| where IsActive and (ValidUntil > now() or isempty(ValidUntil))
| extend IndicatorType = replace(@"\[
| \]
| \""", "", tostring(split(ObservableKey, ":", 0)))
| where IndicatorType == "domain-name"
| extend DomainName = tolower(ObservableValue)
| extend IndicatorId = tostring(split(Id, "--")[2])
| project-reorder *, IndicatorType, DomainName, Type;
  Domain_Indicators
| join kind=innerunique (
  CloudAppEvents
| extend IngestionTime = ingestion_time()
| where IngestionTime > ago(dt_lookBack)
| extend PAUrl = columnifexists("RequestURL", "None")
| extend Domain = tolower(trim('"', tostring(parseurl(PAUrl).Host)))
| extend parts = split(Domain, '.')
| extend tld = parts[(array_length(parts) - 1)]
| extend CloudAppEvents_TimeGenerated = TimeGenerated) on $left.DomainName == $right.Domain
| where CloudAppEvents_TimeGenerated < ValidUntil
| summarize CloudAppEvents_TimeGenerated = argmax(CloudAppEvents_TimeGenerated, *) by IndicatorId
| extend 
          Description = tostring(parse_json(max_CloudAppEvents_TimeGenerated_Data).description),
          ActivityGroupNames = column_ifexists("max_CloudAppEvents_TimeGenerated_ActivityGroupNames", ""),
          ThreatType = column_ifexists("max_CloudAppEvents_TimeGenerated_ThreatType", ""),
          ExpirationDateTime = column_ifexists("max_CloudAppEvents_TimeGenerated_ExpirationDateTime", ""),
          ConfidenceScore = column_ifexists("max_CloudAppEvents_TimeGenerated_ConfidenceScore", ""),
          DomainName = column_ifexists("max_CloudAppEvents_TimeGenerated_DomainName", ""),
          ProviderName = column_ifexists("max_CloudAppEvents_TimeGenerated_IndicatorProvider", ""),
          AlertSeverity = column_ifexists("max_CloudAppEvents_TimeGenerated_ThreatSeverity", ""),
          IPAddress = column_ifexists("max_CloudAppEvents_TimeGenerated_IPAddress", "")
| project CloudAppEvents_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DomainName, ProviderName, AlertSeverity, IPAddress