I'm glad you've got it working.
As you noticed, the embedding code on JuiceboxBuilder-Pro's does not include a baseUrl. (JuiceboxBuilder-Pro has no knowledge of where you might upload the gallery folder to on your web server and the 'index.html' page generated by JuiceboxBuilder-Pro does not need a baseUrl to work as all the gallery files are in the same folder as the HTML page.)
I'm glad that you found the example in the baseUrl support section.
Your embedding code is fine. However, there is one minor point. Your embedding code uses two types of path:
/wp-content/uploads/juicebox/test_13/jbcore/juicebox.js
wp-content/uploads/juicebox/test_13/
The leading slash in /wp-content means that the path is relative to your root directory whereas wp-content (without the leading slash) is relative to the HTML page containing the embedding code.
This works OK in your case as /wp-content and wp-content both resolve to the same location but for consistency (and no other reason), you might want to use the same notation for both paths. (It does not matter which one you choose. They are both equally valid and will both work equally well.)