Earlier quoted context omitted.
You can't use uBlock Origin on iOS?
No extensions.
The problem vis-a-vis uBO that in 2018, Safari switched its extension framework. It no longer supports the WebExtensions framework, instead using a native (proprietary) implementation. The new framework requires extensions to be packaged as apps, and is less featureful in terms of what extensions can do and access than the older framework. Consequently, uBlock Origin decided not to support the new extension framework (https://github.com/el1t/uBlock-Safari/issues/158).