[ REQUEST ] Backdoor whitelist

Hello WRD community,

Recently I have finished making my server-sided executor. Now I want to turn this ss executor into a backdoor, but there are 2 problems: I don't know how to make a whitelist for the backdoor and I don't know how to make it so when a player executes a script in their exploit the backdoor runs. Any help would be greatly appreciated !!!

Sincerely, friendscene