Program.cs

using Microsoft.AspNetCore.HttpOverrides;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorPages();

//ADD: Configure middleware to add X-Forwarded-For and X-Forwarded-Proto headers
builder.Services.Configure<ForwardedHeadersOptions>(options =>
{
    options.ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
    //accept all networks and proxies
    options.KnownNetworks.Clear();
    options.KnownProxies.Clear();
});

var app = builder.Build();

//ADD: use ForwardedHeaders middleware
app.UseForwardedHeaders();


// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

//REMOVE: not needed as nginx proxy server handling https
//app.UseHttpsRedirection();

app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapRazorPages();

app.Run();