The method I found for sideloading Android apps on my Zeekr 7X has been patched, but there is a new way in.
The old method relied on highlighting text on magic.sandboxcar.com to escape the App Labs browser sandbox. The page now sets the CSS properties user-select: none and -webkit-touch-callout: none across the whole page, which disables text selection and the long-press menu, so there is nothing left to highlight.
The new method is simpler than the old one. Instead of escaping through that page, I install YouTube and use its web search to reach a browser. From there, the rest of the process is the same as before: follow the steps in the previous video to install a normal browser and download APK files.
This is still an unofficial method and is not supported by Zeekr. Follow it at your own risk.