For what it's worth, you can try ngn and Dyalog online, since it's licensed to TIO here: https://tio.run/nexus
Other than that there are great book recommendations in the last APL data types thread on HN.
Other than that there are great book recommendations in the last APL data types thread on HN.
I tried meaning of life from FinnAplIdioms on TIO. Sadly it didn't produce any output...
You should also consider "Notation as a Tool of Thought" by Kenneth Iverson (his Turing Award lecture) to be required reading.
I thought I had read it at some point, but now it doesn't ring a bell. Well, it's on the list now. It starts with Babbage quote and uses phrase "tool of thought" which coincides early computer history books I've been reading.
However, if you remove the execute you can still get a string version:
⊖⍕⊃⊂|⌊-*+○⌈×÷!⌽⍉⌹~⍴⍋⍒,⍟?⍳0
42You can paste this into the REPL at TryAPL.org.