I think the clue is you need to own the stock at the time of sailing
2023 is a long way off & you could sell before your cruise
https://d1io3yog0oux5.cloudfront.net/nclhltd/files/documents/Shareholder+Benefit+Offer.pdf
GET EXCLUSIVE PERKS. NORWEGIAN CRUISE LINE HOLDINGS LTD. IS THRILLED TO OFFER OUR SHAREHOLDERS THE FOLLOWING BENEFITS: $250 Onboard Credit per Stateroom on Sailings of 15 Days or More. $100 Onboard Credit per Stateroom on Sailings of 7 to 14 Days. $50 Onboard Credit per Stateroom on Sailings of 6 Days or Less. This exclusive benefit is reserved solely for shareholders owning a minimum of 100 shares of Norwegian Cruise Line Holdings Ltd. at time of sailing. Offer valid for any vacation on Norwegian Cruise Line®, Oceania Cruises® or Regent Seven Seas Cruises ®, excluding charter sailings. Additional terms and conditions may apply.* To redeem this special offer, simply complete the attached Shareholder Benefit Request Form and mail or email (with accompanying documentation) request at least 15 days prior to sailing to