Odoo is generating link for all the tasks in project, these links are for the costumers and along with the link it has access token, which allows any external user to view the sensitive information. I need to know how do i prevent it from generating the access token. 

When i open a link from a with the browser where I am already logged in, it goes to the particular task and on top of the task it displays this "This is a preview of the customer portal. Back to edit mode". Can you please help me with this as i do not want any outsider to access the link with the access token.