asp.net core razor pages erro log to azure code example

Example 1: asp.net core logger in startup

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILogger<Startup> logger)
{
    logger.LogInformation("Configure called");

    // …
}

Example 2: loggerfactory asp.net core 3.0

using (var loggerFactory = LoggerFactory.Create(builder => builder.AddConsole()))
{
    // use loggerFactory
}