Can order ready-made parcel delivery box from Lazada, Shopee or Taobao. Then insert into the front gate pillar. Trouble is to find those parcel boxes with the doors at the back. Most of the standard designs are more suitable for China or other country, where owners open from the frontage of the box.

https://shopee.com.my/product/493705937/130...PBoCtfQQAvD_BwE

For Malaysia, usually we prefer to open the box inside our gates and not front. I have found some suppliers from Taobao that offer multiple  doors for the box. But, the shipping cost is not cheap. So, I decide to find a local supplier to fabricate.