1. 首先，需要在Web API的控制器方法中生成一个随机密码。可以使用下面的代码来生成一个由8个字符组成的密码：

public string GeneratePassword()
{
    const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
    var random = new Random();
    var password = new string(
        Enumerable.Repeat(chars, 8)
          .Select(s => s[random.Next(s.Length)])
          .ToArray());
    return password;
}

2. 接下来，需要使用ASP.NET Core的电子邮件功能发送通知电子邮件。可以使用下面的代码来发送电子邮件：

public async Task SendEmail(string email, string password)
{
    var message = new MimeMessage();
    message.From.Add(new MailboxAddress("Your Name", "your_email@example.com"));
    message.To.Add(new MailboxAddress("", email));
    message.Subject = "New Password";

    message.Body = new TextPart("plain")
    {
        Text = "Your new password is: " + password
    };

    using (var client = new SmtpClient())
    {
        await client.ConnectAsync("smtp.gmail.com", 587, false);
        await client.AuthenticateAsync("your_email@example.com", "your_password");
        await client.SendAsync(message);
        await client.DisconnectAsync(true);
    }

    return Ok();
}

3. 最后，将生成的密码传递到电子邮件发送方法中。完整的控制器方法如下所示：

[HttpPost]
public async Task ResetPassword(string email)
{
    var password = GeneratePassword();
    await SendEmail(email, password);

    // Save the new password to database or other storage.
    // ...

    return Ok();
}

public string GeneratePassword()
{
    const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
    var random = new Random();
    var password = new string(
        Enumerable.Repeat(chars, 8)
          .Select(s => s[random.Next(s.Length)])
          .ToArray());
    return password;
}

public async Task SendEmail(string email, string password)