Arround border

[deep field]

I use this extension (https://github.com/kirevdokimov/Unity-UI-Rounded-Corners?tab=readme-ov-file) to enclose an image with a border.
But in unturned, the border is not surrounded.

[drifting nova]

It is known that AssetBundles do not have compiled scripts.

In other words, the extension uses custom scripts, and those custom scripts aren't compiled and loaded into the game, as the AssetBundle will just save them as regular text based files.

If you wish to make circular icons with square images, simply use a mask like most people.