I am working on a cart checkout based on the TeaCommerce Starter kit. I have added a membership group and all the necessary configuration tags so that a user can log in, buy things and then go to a page only logged-in users can see to download the PDFs they have purchased.

I now want to create a user automatically during the checkout process. I have created a class implementing the ITeaCommerceExtension interface and included the <profile> tags in the config file. My problem is I don't know which event to handle. I have tried "AfterOrderFinalized", which gives me a new member with the correct group. Sadly, he is not associated with his purchases, and is also not logged in.

This is my code for the handler and the SaveMember function:

void MembershipCreator_AfterOrderFinalized(Order order, CallbackInfo callbackInfo)
        {
            // if the user is logged in
            if (Membership.GetUser() == null)
            {
                SaveMember(order);
            }
            Member m = Member.GetCurrentMember();
            order.MemberId = m.Id.ToString();
            order.Save();
        }
        

        void SaveMember(Order order)
        {
            if (string.IsNullOrEmpty(order.Email)) return;
            var chosenGroup = MemberGroup.GetByName("Customer");
            var username = order.Email;
            var password = "password";
            
            var member = Membership.CreateUser(username, password, order.Email);
            Roles.AddUserToRole(username, chosenGroup.Text);

            // Log them in
            FormsAuthentication.Authenticate(username, password); // not working  
        }

A second question is, do I have to save the parameters in this handler (for example, the order)?