no security command on cisco 871

Hello i have a problem on my cisco 871

I have ios 12.4 my image name is c870-advsecurityk9-mz.124-4.t7.bin

I am trying to use :

“security passwords min-length” but on global config there is no “security” command if i use sec ? i only get the “secure” command

Is it something i need to configure in order for the security command to appear?

I am new to cisco routers atm i am on cisco ccna courses.

Thank you