Updated at: 2023-03-19
This article takes iOS as an examcple, how to downgrade YouTube App, you can see this article
When downgrading, you need to pay attention to uninstalling the old version before installing it, and connecting to Brook with the script configured before opening the old version.
https://github.com/txthinking/brook/blob/master/programmable/modules/block_youtube_ad.tengo