I'm assuming it's the NZ working holiday visa. The application opens in Nov (and closes shortly afterwards, depending on demand - "shortly" usually being something like minutes or hours). It is done online through the NZ immigration website
https://www.immigration.govt.nz/new...g-to-new-zealand-to-work/working-holiday-visa.
For a Singaporean, you need to be between the age of 18 - 30. It has a duration of 6 months, activated when you arrive NZ. This must be done within 12 months of the visa being granted. You must leave NZ after the 6 months, but you are allowed to leave and return as many times as you like during this period. Your main intention would have to be for travel, but you are allowed non-permanent work of up to 6 months, in basically anything that is legal and not in the sex industry (not sure how legal they are in the first place). You are also allowed to study.
You also need to have at least NZ $2250 to live on, plus either a return ticket or additional funding to buy the ticket. (NZD - SGD is usually around 1:1). They may want to see evidence of this when you arrive NZ.