In Prestashop, if category is only assigned to customers (loggedin users) then you will see an error message on that category Page that state:

'You do not have access to this category.'

To Force your users to redirect at login page, you have to modify your CategoryController.php file.

Copy file from controllers/front/CategoryController.php and paste into

override/controllers/front/CategoryController.php

Now, inside init function find

if (!$this->category->checkAccess($this->context->customer->id)) {
Remove all code inside this condition and write below code to redirect it to myaccount page:

Tools::redirect('index.php?controller=authentication?back=my-account');



if (!$this->category->checkAccess($this->context->customer->id)) {

Tools::redirect('index.php?controller=authentication?back=my-account');

}