Login API implementation in AccountsController

AccountsController.cs

[HttpPost]
public async Task<IActionResult> Login([FromBody] LoginInputModel loginInput)
{
    var user = await _userManager.FindByNameAsync(loginInput.UserName);

    if (user != null && await _userManager.CheckPasswordAsync(user, loginInput.Password))
    {
        var identity = new ClaimsIdentity(CookieAuthenticationDefaults.AuthenticationScheme);
        identity.AddClaim(new Claim(ClaimTypes.NameIdentifier, user.Id));
        identity.AddClaim(new Claim(ClaimTypes.Name, user.UserName));

        await HttpContext.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme, new ClaimsPrincipal(identity));

        return Ok("Login successful");
    }

    return BadRequest("Invalid Username or Password");
}