I have a Playbase, which I find excellent and better sounding than the Beam.  I discounted Sky Glass for many reasons and not having a dedicated optical out was one.

Have you tried the Sonos HDMI to Optical adapter?  about £25 in the UK.

From what I’ve read “Use this cable to connect your soundbar to your TV's optical audio port” (Arc, Amp and Beam) I require to go from hdmi to optical I’ll keep searching 

Was your extractor an HDMI extractor?  That would be no good because it’s not an HDMI signal that is coming out of the TV.  This might work.  Can you choose to turn off eARC and output over HDMI-ARC?

https://www.amazon.co.uk/Adapter-Converter-Multifunction-BolAAzuL192kHz-Digital/dp/B07Y55NM42

Not something I have done myself so no guarantees.

This is the item I’ve tried 

Do you have a make / model number?

NewBEP 4K@60Hz HDMI2.0b Audio Extractor with 7.1CH Atmos, avedio links HDMI to HDMI with HDMI 7.1CH/ Optical Toslink SPDIF/3.5mm Audio Output, HDMI Audio Converter Support ARC and eARC Fun https://amzn.eu/d/2ReGHqO

Well it claims to do exactly what you want,  So when you say it doesn’t work, you mean just silence?  You do have the eARC output selected in the TV settings?

Model no. OZV2E. 

ToggleSky Glass to EArc from internal speakers and get message

I think I’ll ask a friend to try one of their hdmi sound bars just to make sure hdmi output is working on TV

So have you done what the message advises?  Is there an ARC option in the list?

I’ve found a problem with the converter when the optical is connected there’s no red light coming from the end of the cable and the light on the converter to switch between ARC and eARC switches off . Tried converter on blu ray and no sound a friend had a cheap converter and that worked on the blu ray. Looks like there’s a problem with it. I’ve returned that one and have ordered the one below. I’ll keep you informed thanks for your interest 

HDMI 2.0b Audio Extractor - Tendak HDMI Audio Splitter 4K@60Hz HDMI to HDMI/Optical Spdif/Coaxial / 3.5mm Stereo Audio Converter Support HDCP 2.3 HDR ARC eARC 3D RGB 8:8:8 7.1CH ATMOS https://amzn.eu/d/fHuRHBZ

OK.  Yes please post back.  If that one doesn’t work then I think there is a reasonable chance that the one I linked earlier would (if it is available).

Got it to work not sure how it’s working (see photos) connected HDMI e ARC from tv into HDMI eARC OUTPUT on converter and connected the optical cable and I now have sound. Set sound output on Tv to PCM Stero .I think the Sky Glass most need a signal to allow sound output.