It states in the link below that "This send and receive functionalities are only available through the Creative Cloud Desktop version of the application as it relies on specific technologies to make it possible. This means the Steam or Substance 3D standalone version don't support these features."
That is sad and just pointless then because on the Steam store page for the program it says this.
The perfect companion to Substance 3D Painter. Export your Painter project to Stager in a few clicks. All your texture sets, materials and shader settings will be automatically sent as well. Stager also supports many popular formats like glTF, FBX, OBJ or USD. No matter where you create or find your models, and whether it's characters, weapons, props or vehicles, high or low-poly, Stager can render them in the best light.
You can literally see this in the description, so for them to say that, and then this be an issue where you can see in the link you sent a completely different statement which is stupid (Profanity removed by moderator). This is more than enough of a reason for me to get a refund for stager on steam.