Program.cs

using System.Security.Claims;
using ApiIdentityEndpoint.Data;
using ApiIdentityEndpoint.Models;
using DotNetEnv;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

Env.Load();
    
var builder = WebApplication.CreateBuilder(args);

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var connectionString = Env.GetString("CONNECTION_STRING");
builder.Services.AddDbContext<AppDbContext>(options => options.UseSqlServer(connectionString));

builder.Services.AddAuthentication();
builder.Services.AddAuthorization();
builder.Services.AddIdentityApiEndpoints<User>().AddEntityFrameworkStores<AppDbContext>();

var app = builder.Build();

app.UseSwagger();
app.UseSwaggerUI();
app.MapSwagger();

app.MapGet("/", () => "Hello World!");

app.MapGet("/.", (ClaimsPrincipal user) => user.Identity!.Name).RequireAuthorization();

app.MapIdentityApi<User>();

app.MapPost("/logout", async (SignInManager<User> signInManager, [FromBody] object empty) =>
{
    await signInManager.SignOutAsync();
    return Results.Ok();
});

app.Run();