Elgato Plugin
Companion runs best when it has direct access to your Stream Decks. But in some situations it can be necessary to use them through the Elgato Stream Deck software.
For this, we have a Companion plugin in the Elgato store. You have to enable support for it in the Settings which automatically stops Companion from attempting to use the Stream Decks directly.
You can then drag the actions inside the Elgato software onto buttons on your Stream Deck. These can either be set to a dynamic page, meaning they will follow page changes like directly connected Stream Decks do, or they can be set to show a fixed button.
Remote connection
Since Companion 4.1.5, it is possible to connect the Elgato plugin into Companion remotely. You can setup the IP address of your Companion machine from inside the Elgato Plugin.
This may work in earlier versions, but there are known issues in certain circumstances.