How to connect soundbar to a TV with a skybox

No according to this.

Soundbar with volume passthrough for older television (no ARC)

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Mar 26, 2022 - My parents have an older Panasonic 42 Plasma TH-42PX80U. These were made way before ARC. Looking for options to deliver louder sound for my ...
4 answers · 0 votes: As long as all sources go through the sound system, ARC is not needed at

Is there a AV output on the TV ? Usually either a pair of RCA;s (white/red) or a 3.5mm headphone jack. Try that

Help me connect my soundbar to TV, DVD, and Cable ...

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Jan 2, 2015 - I want to connect my soundbar to give sound from my dvd player and cable box. ... More about : connecting soundbar dvd cable ... SolvedHow do I connectmy Element ELEFW392 TV to my Insignia NS-SB314 soundbar.

How do I connect my sound bar to the TV, BluRay, DVD, and ...

www.tomsguide.com/answers/.../connect-sound-bar-bluray-dvd-dish.htm...

Dec 30, 2014 - Then connected Panasonic Blu Ray DVD player: Panasonic HDMI to TV... pretty hook them up and it works' followed by 'why did you buy a sound bar?' Do Ihave to connect sound bar to TV AND Dish receiver? and not to DVD? ... tv bluraysound bar and a DVR cable box together Forum; Solvedconnecting ...

Soundbar to tv [Solved] - TV - Streaming Video & TVs

www.tomsguide.com/answers/id-2198401/soundbar.html

Help me connect my soundbar to TV, DVD, and Cable ...

www.tomsguide.com/answers/id.../connecting-soundbar-dvd-cable.html

Jan 2, 2015 - I want to connect my soundbar to give sound from my dvd player and... The soundbar has an optical cable option, but my tv does not support that cable. ...SolvedHow do I connect my Element ELEFW392 TV to my Insignia ...

How do I connect my sound bar to the TV, BluRay, DVD, and ...

www.tomsguide.com/answers/.../connect-sound-bar-bluray-dvd-dish.htm...

Dec 30, 2014 - Then connected Panasonic Blu Ray DVD player: Panasonic HDMI to TV... first time, that paired the sound bar to the subwoofer but still no sound. ... Do I have to connect sound bar to TV AND Dish receiver? and not to DVD?

You will need an optical digital audio connection for the TV and the TV will have to be fitted with a compatible "optical digital audio" OUT connection.
The soundbar unit you have does not have an HDMI connection so you only have the one choice with cable..
Any electronics store selling cables will fit you with the correct one.
The one pictured here next to the HDMI cable is the type you need (aka Toslink) but if you don't have an Optical digital Audio Out connection on your TV you have a problem.
HDMI vs optical Which digital audio connection to use CNET

Let me see if I can understand what you want to accomplish.
You have a Panasonic Smart TV, and an LG soundbar. But you want to use a set of headphone. I guess that your TV is already connected to the soundbar, no?
The first thing that you need to check is for an output, it must be from the sounbar, it could be a 3.5mm jack, or an RCA jack. Usually soundbars only have input, meaning that only takes the sound in, never out. If you have an audio output from the TV, you c an always try, but the soundbar won't be use then.

Easy, look at the connections on both the TV and the soundbar. What do they have in common? Hopefully there is a digital audio connector, if so you need a digital audio cable and then use the TV setup to use the DAC instead of built in TV speakers.

If you have connected the optical cable then you should be able to select AV using the TV remote, keep pressing until you hear sound from soundbar!

I do not believe that the vizio soundbar is compatible with anything else besides a vizio :(

At a guess, I would say no.

Your plasma TV likely uses an IR remote control, and although I have seen compatibility issues between IR remote devices, it is extremely rare.

The best way to test it is to remove the skybox and see if that solves the problem.