Why I can’t build honor structure?

Has your alliance built the fist Alliance center yet to place your buildings around? The event also has a small intro tutorial that usually triggers when you first enter the event to let you start doing these actions. Has this happened for you?

If you keep having trouble then close and restart the app. If it is still glitched then you may need to check if you have an update pending for the app. Or possibly even reinstall it. Make sure your game is successfully bound before doing that though.