How to connect over fastboot to Galaxy A50?

I'm on ubuntu 22.04 and I can connect over adb to my Samsung Galaxy A50, and do

adb reboot bootloader

it reboots to bootloader mode, but I can't use fastboot devices, it returns empty. Other phones work in this computer. lsusb shows Bus 001 Device 015: ID 04e8:685d Samsung Electronics Co., Ltd GT-I9100 Phone [Galaxy S II] (Download mode) All tutorials talk about a Windows driver, but what do I do for ubuntu?