How to run shell script continuously and on startup

I am trying to use my Home Assistant install to run the script mentioned in this thread: https://www.avsforum.com/threads/guide-shutdown-formovie-theatre-projector-and-possibly-other-android-projectors-tvs-after-x-seconds-of-sleep.3258402/

Basically, I have a Formovie projector that when it goes to sleep, doesn’t shut down all the way and thus the screen stays up. I want it to shutdown using the script after a specified amount of time.

I made a folder within my config folder using the file browser extension, then I created the specified file in that folder and copied the code into the file and saved. Then, in the command line I wanted to test the file and ran ./projector-shutdown.sh and it just says “./projector-shutdown.sh: Permission denied”

Checking the permissions with ls -l gives me:
-rw-r–r-- 1 root root 1218 Jul 24 20:34 projector-shutdown.sh

Sorry I am very inexperienced with Linux and have no idea what is going wrong.
Thanks for any advice

You need to set execute permission (‘X’) on the file being executed, to start with. Check this out, it should help: