Soluno using web browser settings for PDF

What program does Soluno use for the PDFs? 

How do I find out?

Setting to find what program PDF is defaulted to open with:

First right click on any pdf and you will get a list something like this:

Choose "Open with" and then "Choose another app" from the side list.

This shows the current setting in Windows (in this case Microsoft Edge).

To change it to Adobe Acrobat just click on the "Other Options".  

To Always use Adobe, click on the "Always use this app to open .pdf files".

Setting where PDF is opening in a browser window:

Chrome

Edge (do a find on pdf and you will see the settings):