One way to run svtplay-dl on android/termux

Install F-Droid from
From inside F-Droid, install Termux.
From inside Termux, run:
pkg upgrade
pkg install python
pip install --upgrade pip
pip3 install svtplay-dl
pkg install ffmpeg
#test svtplay-dl
svtplay-dl --version
#optional, enable moving downloaded .mp4 to "normal" android download folder:
mkdir storage/downloads/svtplay_dl
svtplay-dl <svtplay-URL>
mv *.mp4 storage/downloads/svtplay_dl/
exit TERMUX, play *.mp4 in e.g. VLC
This has been tested on
android 10 (should also work on 11),
F-Droid 1.13.1,
Termux 0.117,
svtplay-dl 4.2,
ffmpeg 4.4-1,
Termux app size after these installs: ~673MB
If, later, the python cryptography package is to be upgraded, then the
export CRY...=1
has to be re-issued again first.