You are in the wrong forum. You need to go to a steam forum for an answer.
This forum is for the genuine official Laminar Research X-Plane product. Steam is a 3rd party product taking a commercial advantage of the development work carried out by Laminar Research. Steam installs differently to the Laminar Research version. If you try to purchase steam through Laminar you will be directed away to the steam site.
There is no commercial link between products. Steam will not mix with the Laminar version.
Steam is always behind in updates whereas the Laminar version will give you the option to update, including Beta versions immediately on release.
AS an alternative dump steam with a clean deletion and support the developers by purchasing the genuine product.