Disable dangerous PHP functions

I also can’t figure out how to disable dangerous PHP functions. I have tried like this in my PHP.ini

disable_functions = "exec, system"

But that didn’t work so now I trying this below.

# disable functions
disable_functions=exec,passthru,shell_exec,system,proc_open,popen,pcntl_exec,

add it in php.ini or if using fpm then add it to .user.ini