More Ukrainians should also look into the Matrix protocol as it is end to end encrypted, the service is decentralized and the company that is behind the protocol is based on the UK.
The app element is good app to get started.
Ukraine could have multiple matrix servers for everyone to use.
5 for civilians. 8 for military branches and 3 for government.
maybe they feel it's not safe enough. client is called DSI Merkury 2.0 if you want to look it up more closely
e: lol it's just element clone, they even left original theme in the same shape. it has forced 2FA and as governmental app could be tied to governmental qualified electronic signature infrastructure (every citizen can get one for free) but not sure about it