Have you booked the right cabin category? Basically only sea terrace and rockstar get it.
“Eligible Cabins, Bar Tab: Only the XL Sea Terrace, Central Sea Terrace, The Sea Terrace, Ltd View Sea Terrace and cabins in the Rockstar Quarters Meta Category are eligible for the Bar Tab in the “Wave 2024” Offer. The Bar Tab does not apply to the following cabins: The Insider, Sea View, all Lock It In Rate cabins, and Mega Rockstar Quarters.”