When I booked Apex last fall I immediately was able to book dining in all 4 of their restaurants. I have the Celebrity App. on my phone and was able to use that as well as my computer. We are also booked on Apex for October 2023 but dining is not open for booking yet. We are booked in Aqua for both cruises and I am Elite + so I don't know if that came into play or not. We wanted to try the dining rooms even though I never eat in MDR or at Buffet. Keep checking for the opportunity to book your dining.