Right way to connect a 2nd “extension” center channel speaker?

Situation: TV outputting digital audio through an optical cable to a Sony STR-DE995 receiver. Have a set of Klipsch speakers wired to the receiver. So far, so good.

Problem: need to “duplicate” the center channel, OR the entire sound output, to play through a separate speaker in the kitchen. I can see the TV from the kitchen, but can’t hear a damn thing over all the appliances. Can’t turn up the main system b/c then it’s too loud for the people sitting nearby.

I have a separate mini-amp, like a no-name $ 50 Amazon amp, with RCA input and 2x speaker connections. It’s meant to drive a 2nd sub, but I need it to drive a 2nd center / mixed-channels speaker.

The STR-DE995 has a 2nd Zone output, but it ONLY works on ANALOG inputs. It will not duplicate an optical input to the 2nd zone. Sucks.

I know that I “know enough to be dangerous”, so BEFORE I start DIYing things and burn out something or other, I’m asking what’s the right way to achieve this.

Should I take the wire from the AVR to the Center speaker, and splice in the longer wire to the 2nd Center speaker? If so, in parallel or series? I don’t get the whole 4 / 8 / 16-ohm thing.

Should I take the wire from the AVR to the Center speaker, and wire it to the small amp and then run the 2nd Center speaker from that?

If it’s the 2nd, another question is - the small amp has 4 terminals (L+ L- R+ R-) - how should I wire the speaker to it? Connect both + terminals to the + on the speaker, both - terminals to the - on the speakers? OR bridge the + and - on the amp, and connect the “outer” + and - to the speaker?