To the "Component AV IN" jacks. These are inputs to the TV.
Your second shot shows the Audio out is Optical or HDMI ARC which neither use those RED WHITE audio connections.
As to AUX I don't see AUX in your pictures.
-> OK, rewind. I bet you want to use some old analog speakers. Remember I think you know that you also need an amplifier so the RED WHITE jacks go to the amp and not the (no make, model) speakers.
There are many optical to analog convertors on Amazon so find one and find the BEST SELLERS. I do not give advice on which one but nod to trying the ones in the top 10.
--> Final note: Volume control is moved to the amplifier's duties. The TV remote volume control won't work from here on out.
I have speakers with regular AUX to AUX cable, which used to work fine with my previous TV, but the new TV LG 65UK6100PLB doesn't have an AUX slot.
I bought AUX to RCA, but that still doesn't work.
Which converter do I need to get?
Attached is a photo of the back of the TV.