-----start Python Code-----

from gpiozero import LED 
from time import sleep

led = LED(25)
while True: 
    led.on() 
    sleep(1)
    led.off() 
    sleep(1)

-----endof Python Code-----

Notes:

sudo apt-get install python3-gpiozero

Since the file is executable and is just for your use, create a "bin" subdirectory in  your home "~/bin" that will be added to your path so the file will be recognised by it's short name.
The owner of the files should be you.

References:

https://shahbaz.co/2018/04/07/blinking-led-using-raspberry-pi/

https://docs.xfce.org/xfce/thunar/working-with-files-and-folders#the_file_menu

https://www.raspberrypi.org/forums/viewtopic.php?t=114497