Roon not seeing Oppo

First I must warn you that I am a Technical Moron. So I have Roon on my apple Imac. as the server. I have a android tablet I am trying to use the tablet as a remote for roon. the oppo is the streaming device. It appears that Roon does not recognize the Oppo. Help What should I do?

Which Oppo device? How are you physically connected to it from the imac?

It is a BDP - 103D. It is not physically connected to the i mac. I have roon loaded onto the I mac and have a roon app loaded onto my android device. The android pad can see the oppo but not the roon app.