"Users of Ubuntu 23.10 will be offered an automatic upgrade to 24.04 soon after the release. Users of 22.04 LTS however will be offered the automatic upgrade when 24.04.1 LTS is released, which is scheduled for the 15th of August."
"You can directly upgrade to Ubuntu 24.04 LTS ("Noble Numbat") from either Ubuntu 22.04 LTS ("Jammy Jellyfish") or Ubuntu 23.10 ("Mantic Minotaur")." / NobleUpgrades - Community Help Wiki