Amazon.com: Headphone 3.5mm Splitter Mic Cable for …

Audio/Microphone Headset converters adapter for PC, one 3.5mm female to two 3.5mm male ports The KOOPAO 3.5mm stereo y-splitter cable allows you to easily connect your stereo headset & Mic to a PC audio port and mic port at the same time. enabling you to add a mono microphone input, as well as a stereo output to your PC or Laptop, through a single 3.5mm audio port.

https://www.amazon.com/Headphone-Splitter-KOOPAO-Microphone-Earphones/dp/B084V3TRTV