I use this to make the outputs a headphone jack:
https://www.amazon.com/gp/product/B0010D0HO0/
I power it from this:
https://www.amazon.com/gp/product/B094G1GL8T/
I connect it to the ZOIA with this:
https://www.amazon.com/gp/product/B07GD54Q66/
You're looking for an Audio Interface.
These can range from quite cheap, up to crazy expensive considering they are a key component in modern audio/music production. There are tonnes and tonnes of options.
Some suggestions:
If all you need is one mic input, the Focusrite Scarlett Solo is a good option. It is currently on sale for $119 at Sweetwater.
The Audient EVO 4 for $129 provides a bit more flexibility (two mic inputs/pre-amps) and better software.
Edit: If you've got regular desktop PC speakers with an 1/8" plug you would also need an adapter like this Hosa YMP-434 to connect them to the line out jacks on these audio interfaces.
Thanks for checking in. Glad you like the sound from the Bose. It is an impressive speaker.
A mixer does give you quick and easy control of the volume levels.
It's very unlikely your TV has a Mono audio setting but you don't absolutely need it with the mixer and the Bose.
The cables you need with the mixer are:
2 more XLR cables (for a total of 4)
You would use 2 XLR cables from the outputs of the Innopow into ch 1 and ch2 of the Yamaha. Then 2 more XLR cables to run from the L and R outputs on the Yamaha to CH1 and 2 inputs on the Bose.
And either a new cable or a new adapter to connect the output of the TV into inputs 5/6 on the Yamaha.
https://www.amazon.com/Hosa-CMP-159-Stereo-Breakout-Cable/dp/B005HGM1D6
or this
https://www.amazon.com/Hosa-YMP-434-Stereo-Breakout-Cable/dp/B0010D0HO0
The end result is all the audio will now be connected through the Yamaha and the output is run into the Bose. The settings of CH1 and CH2 on the Bose should be configured exactly the same.
The reverb on CH1 and CH2 of the Bose should be turned off. The Yamaha will now provide the vocal effects.
Hopefully that explanation is clear enough.