Where are the official Xiaomi drivers for ADB/USB? (trying to unlock bootloader of Poco M3)

I tried everything from every tutorial about how to unlock my Xiaomi Poco M3 bootloader. I enabled OEM unlock, etc, rebooted into fastboot mode, but then the phone is not recognized in the batch unlock tool provided by xiaomi at https://en.miui.com/unlock/download_en.html Well, I found https://developer.android.com/studio/run/oem-usb where it lists this weird forum https://web.vip.miui.com/page/info/mio/mio/detail?postId=18464849&app_version=dev.20051 for the xiaomi, which contains a .rar file that when I install I get because the driver is not signed. I don't think I should disable driver signing on Windows, and I find this very weird. I also tried installing Android Studio and then google USB drivers through there, but I still don´t get the phone recognized on the miui unlock tool.