Touchscreen is not recognising pencil

Hello i want to use a pencil as a mouse and keyboard with 7" touch screen but it only detect fingers
i bought this screen: https://es.aliexpress.com/item/32976393963.html?spm=a2g0o.order_list.0.0.3399194dPlh5Ws&gatewayAdapt=glo2esp

the OS im using is armbian

this is the link of the screen:

http://www.lcdwiki.com/7inch_HDMI_Display-C?spm=a2g0o.detail.1000023.18.7f2f1448V10EEZ

i have other 4" screen with a raspberry pi 2 and it works with pencil.

to be more specific the 7inch screen work only with fingers not pencil.
what can i do?

The aliexpress links says:

  1. Touch: five-point capacitive touch

so it can only support finger, not pencil. what pencil are you using?