The latest fedora supports tpm unlock of secrets for encrypted luks partitions. This includes the root partition. It is a good idea to have a strong passphrase on the partition also as a backup.
In theory, ubuntu could do this as well. It worked for me (with initramfs and some custom code) up until 25.10 but as of 26.04 it seems impossible.
I can't get ubuntu/kubuntu 26.04 to work with LUKs2 encrypted root partitions at all. I used to be able to hack it together but not anymore as the installers cannot setup proper booting. Both installers crash and I have not been able to manually finish the setup to make booting work in resuce mode (liveusb). In theory if we can get it installed it should work the same as fedora. Everyone seems to be moving to dracut and systemd for the boot process.
assuming we installed fedora with luks2 encrypted root and did not find the tpm option this is how we manually set it up. Before starting this we get a password prompt on boot for decrpt. Run these commands to setup tpm unlock.
sudo systemd-cryptenroll --tpm2-device=auto --tpm2-pcrs=7 /dev/nvme0n1pX
mv /etc/crypttab /etc/crypttab.orig && cp -a /etc/crypttab.orig /etc/crypttab
sed -i 's/$/,tpm2-device=auto/' /etc/crypttab
dracut -f
after reboot the password prompt should not display for decrypt of the root partition.