Hello everyone.
I'm trying to connect my usb modem to r2s with friendlywrt 19.7.1, but i am faced with similar problem when installing packages:
Unknown package 'kmod-usb-serial'.
Unknown package 'kmod-usb-serial-option'.
Unknown package 'kmod-usb-serial-wwan'

Has enyone met a similar problem and how did you solve this?
System - clean image and repos have not changed