The 2021 Meta Portal Plus (codename cipher) has a panel fixed in landscape orientation with no rotation, only a tilt mechanism. Some apps are locked to portrait-only mode and these instructions outline how to download and modifify apps from the Google Play Store to force landscape mode.
Note
The Target app in this example is jp.or.nhk.nhkworld.tv (NHK WORLD TV), versionCode 21259021. These instructiosn were preapred on macOS, so sed uses the BSD -i '' form; substitute -i for GNU sed.