You're in Indonesia (so the brands we know here in the states might not be available to you where you are)
For a baby sulcata tortoise I like to use orchid bark. Go to a plant nursery - a place that sells plants/gardening stuff, etc. See if they have fir bark, or even cypress mulch. But really any hardwood bark would be fine. But you want a product that is very small, not big chunks, which would be hard for a baby tortoise to walk on.
As a last resort, you can go out into your yard and dig up some clean dirt. By clean, I mean you have never sprayed any pesticides or herbicides on it. If you buy dirt at the store, you don't want something that has additives like chemicals or perlite, etc. I can't really see the product through the bag in your picture.
I was told by my breeder told me to use Coconut Coir with sphagnum moss mixed in to hold in moisture. the coco coir can be found in any pet store and is either loose powder or brick like and you mix it with water. Pretty simple and good substrate. My sulcata loves it and is very happy.