Which script, myshell or autorun?
If it's myshell, connect to your Kobo using SSH and try to run your script. You can connect with SSH using KoboLauncher. Read this post:
https://www.mobileread.com/forums/sho...21#post2401521
and from post #112 to post #118:
https://www.mobileread.com/forums/sho...91#post2502791
Download link is in the first post.