@Yael ************
these were what I submitted:
1. Business registration proof/license that has my name as owner of the business, and was issued by Singapore government officially. This pdf also showed what kind of industry I was in, which matched my portfolio
2. my portfolio. I am in the ecommerce industry so screenshots of my site was enough
That was all to prove my business. On top of that, my bank statements also showed money coming in and out that were labeled as business transactions/sales, reflecting my business name as well