When I use OpenTelemetry.Metrics library for use metrics of “System.Net.Http” namespace or other systems metrics, then I get metric and labels in format.

How to set default context name for metric and labels like this (prefix – “application”)?
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Try to set prefix of application into metric name:

 var builder = WebApplication.CreateBuilder(args);
 
 builder.Services.AddConnections();
 builder.Services.AddEndpointsApiExplorer();

 builder.Services.Configure<MetricsPrometheusOptions>(o => 
 {
     o.MetricNameFormatter = (a, b) => $"TestM_{a}_{b}";
     o.LabelNameFormatter = (a) => $"TestM_{a}";
 });
 builder.Services.AddOpenTelemetry()
     .ConfigureResource(resourceBuilder => resourceBuilder.AddService("test_metrics"))
     .ConfigureResource(t => t.AddService(
         serviceName: builder.Configuration.GetValue("AppName", defaultValue: "test-metrics")!,
         serviceVersion: typeof(Program).Assembly.GetName().Version?.ToString() ?? "unknown",
         serviceInstanceId: Environment.MachineName))
     .WithMetrics(x =>
     {
         x.AddHealthChecksInstrumentation(a => a.IncludeHealthCheckMetadata = true);
         x.AddPrometheusExporter();
         x.SetMaxMetricPointsPerMetricStream(19000);
         x.AddHttpClientInstrumentation();
         x.AddAspNetCoreInstrumentation();
         x.AddRuntimeInstrumentation();
         x.AddBuiltInMeters();
     });

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