如何在Serilog Azure App Insights Sink中排除AppRequests日志

我正在开发ASP.NET应用，使用Azure AppInsights及Serilog Sink推送日志。但AppInsights中产生了大量无关的AppRequests（GET/POST）日志，导致Azure订阅成本大幅增加。我尝试通过Type字段和仅AppRequests表有的Url属性进行排除，但均失败，仍能看到所有AppRequests日志，附上appsettings.json配置及日志截图，求问问题出在哪？

appsettings.json：

"Serilog": {
      "Using": [ "Serilog.Sinks.Console", "Serilog.Sinks.ApplicationInsights", "Serilog.Expressions" ],
      "MinimumLevel": {
        "Default": "Debug",
        "Override": {
          "Microsoft.AspNetCore.Mvc.ModelBinding": "Warning",
          "Microsoft.AspNetCore.Routing": "Warning",
          "Microsoft.AspNetCore.Cors.Infrastructure.CorsService": "Warning",
          "Microsoft.EntityFrameworkCore.Infrastructure": "Warning"            
        }
      },
      "Filter":[
        {
          "Name": "ByExcluding",
          "Args": {
            "expression": "IsDefined(Url)" // 我也试过"Type = 'AppRequests'"但无效
          }
        }
      ],
      "WriteTo": [
        {
          "Name": "Console"
        },
        {
          "Name": "ApplicationInsights",
          "Args": {
            "connectionString" : "InstrumentationKey=7aa4cc33-fb03-4b4c-81b8-7a257c083a6e;IngestionEndpoint=https://westeurope-1.in.applicationinsights.azure.com/;LiveEndpoint=https://westeurope.livediagnostics.monitor.azure.com/",
            "restrictedToMinimumLevel": "Debug",
            "telemetryConverter": "Serilog.Sinks.ApplicationInsights.TelemetryConverters.TraceTelemetryConverter, Serilog.Sinks.ApplicationInsights"
          }
        }
      ],
      "Enrich": [ "FromLogContext" ]
    },

AppRequests日志截图：

内容的提问来源于stack exchange，提问作者Yehia A.Salam