@dzipo38 

Below is the instruction to setup parental control on the Archer C9.

https://www.tp-link.com/support/faq/1531/

Please notice that the internet access time is not the time period when you can access internet, instead, the parental control rule will take effect during this time. 

For the whitelist, the devices can access the allowed websites only during the internet access time, vice versa. 

Besides, you can select 24/7 all days as internet access time, choose whitelist but no keywords. After that, please confirm whether you can access internet. 

Note: Theoretically, the internet won't work. 

May it help and have a nice day.