Program.cs

using System.Text;
using CPMApi.Models;
using CPMApi.Services;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using Microsoft.OpenApi.Models;

var builder = WebApplication.CreateBuilder(args);

builder.Services.Configure<DatabaseConfiguration>(builder.Configuration.GetSection("Database"));
builder.Services.Configure<LoginConfiguration>(builder.Configuration.GetSection("Login"));
builder.Services.AddSingleton<UsersService>();
builder.Services
    .AddControllers()
    .AddJsonOptions(options => options.JsonSerializerOptions.PropertyNamingPolicy = null);
builder.Services.AddEndpointsApiExplorer();
builder.Services
    .AddAuthentication(options =>
    {
        options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
        options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
        options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
    })
    // Adding Jwt Bearer
    .AddJwtBearer(options =>
    {
        options.SaveToken = true;
        options.RequireHttpsMetadata = false;
        options.TokenValidationParameters = new TokenValidationParameters()
        {
            ValidateIssuer = false,
            ValidateAudience = false,
            ValidAudience = builder.Configuration.GetSection("Login")["Audience"],
            ValidIssuer = builder.Configuration.GetSection("Login")["Issuer"],
            IssuerSigningKey = new SymmetricSecurityKey(
                Encoding.UTF8.GetBytes(
                    builder.Configuration.GetSection("Login")["Key"]
                        ?? throw new Exception("Key is missing from the login configuration")
                )
            )
        };
    });
builder.Services.AddSwaggerGen(option =>
{
    option.AddSecurityDefinition(
        "Bearer",
        new OpenApiSecurityScheme
        {
            In = ParameterLocation.Header,
            Description = "Please enter a valid token",
            Name = "Authorization",
            Type = SecuritySchemeType.Http,
            BearerFormat = "JWT",
            Scheme = "Bearer"
        }
    );
    option.AddSecurityRequirement(
        new OpenApiSecurityRequirement
        {
            {
                new OpenApiSecurityScheme
                {
                    Reference = new OpenApiReference
                    {
                        Type = ReferenceType.SecurityScheme,
                        Id = "Bearer"
                    }
                },
                new string[] { }
            }
        }
    );
});

var app = builder.Build();
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}
app.UseHttpsRedirection();
app.UseAuthorization();
app.MapControllers();
app.Run();