Smartthings, Samsung SHAPE/Multiroom Speakers and Google Home

Hello. I currently have a mix of Samsung SHAPE/Multiroom Speakers (M3, M5, M7, H750 soundbar, WAM270 soundlink) and want to understand the capability to control them with my Samsung Smartthings Hub and Google Home.

I have done the integration between the Samsung Speakers and Smartthings - most of the speakers appear as “Devices”.
I have integrated the Google Home Voice Control Speaker with Samsung Smartthings via the Google Home app.

Questions:

How do I control the Samsung Speakers with the Google Home using voice commands?
How do I manually add two Samsung speakers that Smartthings cannot “find” when I do a manual search?

Thank you in advance for this Forum’s help