In order to test that Venue Server finds the Scores app, you do not need to wait to be on the venue. You can do the test anywhere by just having the Scoring Computer and the Venue Server Computer in the same network.
We recommend that no other applications are run on the Scoring Computer, but the Venue Server can run on the same computer that, for example, Possession Tracker or some graphics application.
This an example of the test set-up
With these steps, the applications should connect automatically.
Prior the testing, you need to, of course, install the Venue Server application.
First, go to https://vs.scores.fiba3x3.com/ and select your operating system.