Hi,

activate the technical features for user.

To activate the technical features, you have to add access rights to your user. You must edit your current user from the menu Settings > Users. Edit your user and, in the Access Rights tab, check the option Technical Features.

now you can seee menu Product Categories.

Sales>>Configuration>>Product s>>Product Categories

or

Purchases>>Configuration>>Products >>Product Categories

or

Warehouse>>Configuration>>Products>>Product Categories