How to add an obstacle?

[magickaito]

Hi experts here

Super love this. I want the liquid to avoid an obstacle, let's a rectangle at certain x and y. Any hints how can it be done?

[rmxzyz]

same for me, look at this one https://sandspiel.club/ and it has that but i dont know how to do that.

[MiracleCK]

您好，我已经收到你的信件！我会及时阅读并作出回应！