They are all systems requiring a WordPress user. Because of this you must use the “WP user sync”.
If you don’t know what it is, please check PrivateContent’s documentation: there’s a dedicated chapter about this.
Basically:
- enable WP user sync
- each user must be synced
- use the “roles emulation” to integrate with the desired plugin
For example, to let PrivateContent users to interact with WooCommerce you have to emulate the “Customer” role