I don't have a Raspberry Pi, but they recommend to do
sudo apt-get update
sudo apt-get install wolfram-engine
it should somehow go with the so called wolfram-engine. Without installing something WolframLanguageScripts nothing will happen, WolframScript, you can also do at the prompt
$ find / -type f -name "*olfram*cript" -print 2>/dev/null
to find it on your machine with the bash, if it is already installed.
