They are a sophisticated third-party scam.
In the midst of a hectic family trip, with several family members feeling unwell, we were rushing to complete the required travel arrangements. Unfortunately, we mistakenly submitted our information through this scam website, believing it was the official Singapore arrival form. As a result, we were unexpectedly charged USD $285. We then waited at the airport for our application to be approved, unaware that the official Singapore arrival form can be completed free of charge in just a couple of minutes at the gate before immigration. The website was designed to closely resemble an official government service, making it very difficult to recognise that it was a third-party scam. We only realised this after arriving at the airport, by which time the charge had already been processed.