Updating Telegram desktop on arm64 ubuntu 21.04

The apt version of telegram-desktop is not updated during the lifecycle of an Ubuntu release, due to reasons described here.

The snap package for telegram-desktop has arm64 builds, and it hosts the latest version. Uninstall the old version of telegram (sudo apt remove telegram-desktop, assuming you installed with apt), and enter the following commands in a terminal.

sudo apt install snapd
sudo snap install telegram-desktop

The flatpak version also hosts arm64 builds.

sudo apt install flatpak
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
flatpak install flathub org.telegram.desktop