Rovelli is a proponent of what he calls the "relational interpretation" of QM, which basically states that particles only have properties when they interact with other systems (and may be better thought of as events than persistent objects). Entanglement is a general phenomenon that describes the relationship between two interacting systems and a third which hasn't interacted yet. Put another way, something can be real in relation to A but not to B. However, the correlation that entanglement guarantees ensures that previously isolated systems will see the same things if they do eventually intersect.
It's different from QBism because there is no special privileging of human observers; all physical systems exist in direct interaction with some systems, are in superpositions in relation to others, etc.
[1]: https://bookshop.org/books/helgoland-making-sense-of-the-qua...