Let' see the parameters

lenght: is the password length (default = 8)

use_upper: set to 0 if you do not want to use uppercase chars (ABCD...), any other value otherwise. Default = 1

use_lower: set to 0 if you do not want to use lowercase chars (abcd...), any other value otherwise. Default = 1
use_number: set to 0 if you do not want to use number chars (0123...), any other value otherwise. Default = 1

use_custom: a string representing any extra char you want (such as ?*_ ...). Default = empy string