Translation:May prosperity be with you!
Sounds more like 'May the force be with you' than a New Year's greeting. For the latter, 'May you be prosperous' or 'May you prosper' (in the new year).
This sentence translates directly as congrstulations and good fortune. It should be taught though as "good luck this year" or some such because it is only used at new year.
The hints say 'congratulations' and 'make a fortune'. No way of sucking 'may prosperity be with you' out of that...
Isn't this a set phrase? Meaning: may you have a prosperous New Year.
Doesn't 恭喜 mean congratulations? how did it translate to may you have prosperity I don't get it
It does not literally translate. It is a set phrase, an idiom. There are a lot of set phrases and vocabulary that do not translate literally. You just have to learn them over time.