User.cs

public record NewUser(Guid RequestedByUserId);
public record ResetPassword(Guid RequestedByUserId);

public class User
{
    public Guid UserId { get; private set; }
    public string Pasword { get; private set; }
    
    public void ResetPassword(Guid requestedUserId)
    {
        if (UserId != requestedUserId)
        {
            throw new UnauthorizedAccessException("You are not allowed to reset another users password.");
        }
        
        Pasword = PasswordGenerator.Temp();
    }
}

public class RestPasswordHandler
{
    private readonly DbContext _dbContext;

    public RestPasswordHandler(DbContext dbContext)
    {
        _dbContext = dbContext;
    }
    
    public void Handle(ResetPassword request)
    {
        var user = _dbContext.GetUser(request.RequestedByUserId);
        user.ResetPassword(request.RequestedByUserId);
        _dbContext.Save(user);
    }
}

public class NewUserHandler
{
    private readonly DbContext _dbContext;

    public NewUserHandler(DbContext dbContext)
    {
        _dbContext = dbContext;
    }
    
    public void Handle(NewUser request)
    {
        var user = new User();
        user.ResetPassword(request.RequestedByUserId);
        
        _dbContext.Save(user);
    }
}