How do you get the Endless War Icon?
It was a mission or event reward. Riot's description in the client reads: “Earned by participating in the 2018 VS. event to celebrate Darius' victory over Garen.”
Is the Endless War Icon still available?
No. Riot tied the Endless War Icon to 2018 (mission reward), and it does not normally bring back past event rewards or bundles.
