PULSE 2I x 2 in stereo mode with Roon

Dear,

I am interested in purchasing 2 x Pulse 2I so I can listen in stereo.

I suppose setting up in stereo is done true the Bluos app.

But now I use ROON with my traditional stereo system (amplifier + passive speakers)

How do I set up ROON with the 2 x Pulse2I so that they work in stereo ? 

I have no idea how to do this with 2 x Pulse2I

Thank you

Jean-Yves