Thanks for your answer !
I’ve setup a relationship field filtered with my CPT, displayed on the add/edit form of a user.
I can now see this field and select one or multiple page of my CPT for each user.
I will now have to check via PHP if a user have restriction on a specific page.
This field will also be edited via API from my CRM, from what I saw in your documentation, it’s possible.
Is it the good way to go ?