New install: No wifi access for apt install <wifi driver>

Dear all

I'm a new to Kali, and have just installed it onto a partition on brand new Lenovo Yoga laptop. The rest of the laptop has Ubuntu 18.04 (also just installed), and every device works fine from Ubuntu.

I'm not able to get started in Kali as--although the install is complete and Kali boots up--I don't have any way to access the Internet. The Wifi hardware is Intel 8265/8275, but I can't find any way of downloading this offline (to a USB) and installing it on the hard-disk.

I tried connecting by tethering my mobile phone as well another broadband data dongle, both through USB. Neither way worked.

Can anyone point me to a way out of this chicken-and-egg problem?

TIA