During their journey to Alabasta, they were trying to help Vivi save her country from the clutches of Crocodile.

Source: https://gamerant.com/one-piece-sanji-best-achievements/

More recent arcs also feature beautiful princesses like Vivi, and Rebecca — whose skills and potential leadership abilities have been shoved aside to the point of obscurity.

Source: https://www.cbr.com/one-piece-female-character-designs-beauty-standards/

Select products from Vivi Imports will be featured throughout the meal.

Source: https://torontolife.com/insider/what-tl-insiders-can-look-forward-to-in-april-2/

The fact is that Vivi is going to be central to this part of the story, meaning that she's going to be a very important character going forward.

Source: https://gamerant.com/one-piece-vivi-true-importance-explained/