Try:

Where it says #CHANNEL change this to your channel name.

I changed the if ($nick isop #) to if ($nick !isop $chan)

It seems to work on IRC channel. I've never worked with twitch.


Code:
on *:TEXT:!arab:#CHANNEL: {
  if ((%floodarab) || ($($+(%,floodarab.,$nick),2))) { return }
  if ($nick !isop $chan) { .msg $chan $nick %variablename }
  else { .msg $chan You aren't able to use this command. }
  set -u30 %floodarab. $+ $nick On
  .msg $chan ARAB RULES: 1. At shaper select, hit random, but DO NOT LOCK IN 2a. Stay in bottom lane 2b. You may not enter any bushes other than the 2 in  the middle of the bottom lane 2c. You may not walk behind any wall 
 .msg $chan 3. wards are allowed everywhere you are allowed to walk 4. you may not retreat to the top binding near your  guardian for safety. 5. you may not retreat to the base for saftey or healing 6. you may not buy anything unless you die (or at beginning of the match)  $+ 
}