RCA to Speaker Wire Adapter, 2 Bare Wire Speaker Cables to RCA Plug Adapter for Audio Video AV Receiver TV Subwoofer - 20AWG, 6.6ft

RCA to bare wire speaker cable would probably be easiest. Example: https://www.amazon.com/caojunzhen-Speaker-Adapter-Receiver-Subwoofer/dp/B0DYF66TXP