How do i use this in the editor?

This map doesn't appear under combined arms or domination modes but the other listed modes. Is that a glitch?

nice map, only complaint i have about it is the water clipping through the ground

You need to have a paid version of the game. Then subscribe to it in steam workshop. Wait for it to download. Start the game and go to workshop tab in main lobby. Find map and select activate then click apply down bottom of page. Map is now in the collection of maps for you to choose when you host a game.

how do I install a map for Call to arms?