Urgent - Can’t get raspberry pi 4 to run a simple script on startup

I’ve tried every single tutorial and forum post I could find to get it to just run a small script that I’ve written that launches a Processing sketch file. - The script is set to be executable - The path is /home/notions/startup.sh What I’ve tried already - Editing rc.local - Editing .bashrc (this works but I have to manual open the terminal first - I’ve tried autostarting the terminal with @lxterminal in the autostart file - Tried editing crontab -e - Tried systemd No matter what I try, whenever I reboot the Pi it just won’t autostart anything. Any advice or help would be hugely appreciated. I’m under time pressure for a project

Show the content of the script. Show how you have entered this in the crontab.