My code is not working.

Made in Skript.

It says it cannot parse the code.
I am on Minecraft version 1.21.4.

I expect it to ban the player and also keep them banned when they join again.

on join
  if {ban.&player&} is 1:
    ban player


command ban player:
    ban arg-1 for 10 years for "banned"

I am new to Minecraft and Skript. What is the error in my code?