FajarNurhadi Hey! You can check compatible devices for eSim at the website esim<dot>sm.
Unfortunately, the (3a) model does not support eSim:

What you see in the settings is most likely a placeholder option in NOS 4.0. It could happen that the system shows menu items that exist on other models (such as (3a) Pro)😔
[EDIT]
RapidZapper Oh that’s interesting, I didn’t know about this.
Yes indeed, it is mentioned on the official website for the (3a), under Connectivity tab eSIM is available only in Japan