The attached .txt file describes how to install get_iplayer on a non-rooted phone, running a Ubuntu distribution on UserLAnd (app from Play Store).  Only the command-line interface is used.  Adding a desktop environment is possible, but I don’t think it is worth the effort or the overhead.  I just use  get_iplayer to download the programmes to the phone’s external SD card; then play the downloads (mp4 video and mp4a audio) in Android.  Linux distributions with apps like UserLAnd tend to have a minimal base system, so that’s why additional steps are needed where expected functions are missing.  It’s a bit easier if you are familiar with Linux systems like Ubuntu and use of command-line.
UserLAnd does not root your phone and if you do not like it - just uninstall the app.
get_iplayer android.txt