You'll need flatpak-builder to build the image.
Pull the git repo and run flatpak-builder --user --install --force-clean build-dir com.microsoft.AzureStorageExplorer.yaml for test installation.
On KDE, you may need either KWallet with KDE Frameworks version >5.97 or a different secrets manager. Because of Kwallet's implementation of org.freedesktop.secrets isn't supported by keytar you may run into issues with KWallet. An easy solution is using gnome-keyring or KeepassXC secret service. For Kubuntu 22.04 LTS, you need to enable backports.