Yeah you need a separate dongle. The ZBDongle-E from Sonoff is pretty cheap on AliExpress. Cheaper than the official Home Assistant ZBT-1 dongle Nabu Casa sells. Unfortunately running both Zigbee and Thread on one antenna doesn’t work very well even with the dongle from Nabu Casa.

Only thing with the ZBDongle-E is that you need to flash it yourself to run OpenThread via this website https://darkxst.github.io/silabs-firmware-builder/ it’s not hard though.