Ive been lookin like hell for it, but it doesn’t seem like it. Seems as though Arch has v2.5, but Debian and deb Sid dont. I can only suggest trying to install from either flatpak, or snap, barring that you could try to build it from source If that’s your thing.
Here’s a copy pasta script for snap:
sudo apt update ;
sudo apt install snapd ;
sudo snap install core && sudo snap install onionshare
Here’s some copy pasta for flatpak:
su - ; apt install flatpak ;
apt install gnome-software-plugin-flatpak && flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo ;
reboot
Finish reboot, login, copy pasta this to finish flatpak
flatpak install flathub org.onionshare.OnionShare && flatpak run org.onionshare.OnionShare