Host on IIS with InProcess mode:

web.config

<system.web>
  <httpRuntime maxRequestLength="52428800" />
</system.web>
<system.webServer>
  <security>
    <requestFiltering>
      <!-- change the max to 50 MB -->
      <requestLimits maxAllowedContentLength="52428800" />
    </requestFiltering>
  </security>
</system.webServer>

Startup.ConfigureServices

services.Configure<IISServerOptions>(options =>
{
    // 50 MB
    options.MaxRequestBodySize = 52428800;
});

services.Configure<FormOptions>(options =>
{
    // 50 MB
    options.MultipartBodyLengthLimit = 52428800;
});

Host by Kestrel

Program.cs

public static IHostBuilder CreateHostBuilder(string[] args) =>
    Host.CreateDefaultBuilder(args)
        .ConfigureWebHostDefaults(webBuilder =>
        {
            webBuilder.ConfigureKestrel((context, options) =>
            {
                // Handle requests up to 50 MB
                options.Limits.MaxRequestBodySize = 52428800;
            })
            .UseStartup<Startup>();
        });

Host on nginx

.conf

client_max_body_size 50m;