Greetings,
I presume you meant to say that you are on Pro Tools 2019.10, yes? Dolby Audio Bridge needs to be visible in Applications > Utilities > Audio MIDI Setup > Audio as a valid Core Audio driver before it can be used including in Pro Tools.
Here are the system requirements for DAPS 3.5 and Pro Tools:
https://developer.dolby.com/globalas...ease_notes.pdf
(page 27)
I'm going to guess that you never allowed the system extensions to be able to be loaded:
https://professionalsupport.dolby.co...language=en_US
Let us know.
Jeff