Lua Anchors are places where lua code can be triggered through Hooks.
The anchors hook is triggered every frame. The hook name is always "onAnchor:ANCHOR NAME".
Example:
game.addHook("onAnchor:new_game_left", function()
if imgui.Button("print", { -1.0, 0.0 }) then
game.print("test print")
end
end)