I've seen people commenting on many workshop mods asking how they can make subscribed mods appear in the mods menu in Noita. To do this, it's very easy:

In your Steam Library, right-click on Noita and select "Properties".

In the properties window, go to the "Betas" tab.

Select "noitabeta" as your desired branch from the drop-down menu.

Let Steam update Noita, and you when you launch Noita, you should see your subscribed mods in the mod selection menu.

Happy modding, everyone!