Lua script

Hello, i don't know if i can get an answer for this, but still, i cannot find for the love of god the .lua script for the calc, i've searched and i cannot find it, i was sent on github where there was an actual .lua script but it didn't seem to be downloadable, so i'm asking if anyone knows where and how to download the script for the calc. ie: sending the link, if it's possible

thanks in advance