With The Queen’s passing, Prince Charles accended the throne as King Charles III. His wife Camilla is entitled to share all her husband’s titles and is automatically entitled to be called Queen (consort).
Just a few months ago, a statement was released by Queen Elizabeth II which stated that she supported Camilla becoming Queen (consort) when the time came. Camilla is legally entitled to be called Queen (consort), but an announcement at the time of her wedding to Prince Charles stated that she was to be called Princess consort. This was likely an attempt at appeasing those who opposed the wedding, and it had no basis or precedent.
As Queen (consort), Camilla is addressed as Her Majesty The Queen, even if she is not a Queen regnant as her mother-in-law was. The consort part is not used when addressing The Queen. If Charles predeceases her, she may follow the precedent of Queen Mary, the wife of King George VI, and be known as Queen Camilla to avoid confusion with the new Queen (consort).