If you're having trouble bootstrapping via the web applications here are some commands you can run manually from within rescue mode. Replace amd64 with arm64 in the Talos image download URL according to your architecture.
Hetzner bare metal:
# Stop Raid if enabled
mdadm --stop /dev/md[0-4]
# Wipe disks
sfdisk --delete /dev/nvme[0-1]n1
wipefs -a -f /dev/nvme[0-1]n1
wget https://github.com/siderolabs/talos/releases/download/v1.3.7/metal-amd64.tar.gz --quiet -O - | tar xvfzO - | dd of=/dev/nvme0n1 status=progress
sync
mount /dev/nvme0n1p3 /mnt # assuming that p3 is the BOOT partition, can make sure with `gdisk /dev/nvme0n1` and `s` command
vi /mnt/grub/grub.cfg # add talos.config=https://<app-host>/config?uuid=${uuid}
umount /mnt
reboot
Hetzner cloud:
sfdisk --delete /dev/sda
wipefs -a -f /dev/sda
wget https://github.com/siderolabs/talos/releases/download/v1.3.7/metal-amd64.tar.gz --quiet -O - | tar xvfzO - | dd of=/dev/sda status=progress
sync
mount /dev/sda3 /mnt # assuming that sda3 is the BOOT partition
vi /mnt/grub/grub.cfg # add talos.config=https://<app-host>/config?uuid=${uuid}
umount /mnt
reboot