Use the latest version found here: https://unfinishedbitness.info/2022/07/17/action-library-v1-5/
A few people have been following the Action! posts and attempted to compile the code only to find there were some missing unpublished routines (unfinished bits 😉 ). The routines do in fact exist. I thought I had published all of it in pieces, apparently not. Attached here is the complete library. You will need to remove the .ODT file extension leaving just .ATR. It is NOT an ODT file, WordPress wouldn’t allow the ATR file type.
Hopefully it helps you.