Serilog UWP Background Task

Question

i'm having some issues using serilog while running a background task in an uwp app.

I'm using appsettings to configure, but no log is being done.

  "Serilog": {
    "WriteTo": [
      {
        "Name": "File",
        "Args": {
          "path": "%BASEDIR%/logs/log.txt",
          "rollingInterval": "Day",
          "retainedFileCountLimit": 30,
          "shared": true
        }
      }
    ]
  }

and in my background task i'm doing this:

Environment.SetEnvironmentVariable("BASEDIR", ApplicationData.Current.LocalFolder.Path);
var configuration = new ConfigurationBuilder()
    .SetBasePath(ApplicationData.Current.LocalFolder.Path)
    .AddJsonFile("appsettings.json")
    .Build();

Log.Logger = new LoggerConfiguration()
    .ReadFrom.Configuration(configuration)
    .CreateLogger();

What i'm doing wrong? Or missing?