Program.cs

using Azure.Identity;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using Microsoft.OpenApi.Models;
using Swashbuckle.AspNetCore.Filters;
using System.Text;

var builder = WebApplication.CreateBuilder(args);

if (builder.Environment.IsProduction()) {
    var keyVaultEndpoint = new Uri(Environment.GetEnvironmentVariable("VaultUri"));
    builder.Configuration.AddAzureKeyVault(keyVaultEndpoint, new DefaultAzureCredential());
}

// Add services to the container.

builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen(options => {
    options.AddSecurityDefinition("oauth2", new OpenApiSecurityScheme {
        Description = "Standard authorization header using the Bearer scheme (\"bearer {token}\")",
        In = ParameterLocation.Header,
        Name = "Authorization",
        Type = SecuritySchemeType.ApiKey
    });

    options.OperationFilter<SecurityRequirementsOperationFilter>();
});

builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
    .AddJwtBearer(options => {
        options.TokenValidationParameters = new TokenValidationParameters {
            ValidateIssuerSigningKey = true,
            IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(builder.Configuration["SymmetricSecurityKeyToken"])),
            ValidateIssuer = false,
            ValidateAudience = false
        };
    });

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment()) {
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.UseAuthentication();

app.UseAuthorization();

app.MapControllers();

app.Run();