Task tracker, in which you can let the customer?

Question

Time Management

Hello!
Please advise a task tracker in which the following process can be implemented:
1) The customer creates a task.
2) The task is condemned with the manager by the performer.
3) Then the manager assigns the task to the executor (developer), while the task must be copied to some other project or to some area where the customer will not be able to see the "inner kitchen" of the executor. Those. so that the progress of the task and its discussion within the team is hidden from the customer.
4) After completing the task, the developer closes the task.
5) The manager checks the result and closes the top-level task that the customer created.
In general, it is clear that you can simply copy-paste or copy tasks to another project (internal), but I would like to find some kind of tracker where this process will somehow be automated and will not require additional actions.
Thank you all in advance for the tips!

Answer 1

Asana , it has guest access for left people.

Answer 2

You can use any developer tracker or generic Service Desk system:
This is a minimal list, as there are many more systems. For your task, the simplest one will do (for example, wrike)