Surface Pro 7 Line in not working........

[spywiz]

I have a Microsoft Surface Pro 7. It has a combination Headphone/Microphone jack on the top left of the screen. I am having a hard time figuring out how to use this jack as a Line-In for my Uniden SDS-100 and Proscan. If anyone can help me figure this out, please speak up. Thanks.

 

[wtp]

someone else said it need a splitter for four connections inside the laptop.

Amazon.com: 3.5mm Headphone Splitter Adapter, MillSO CTIA Audio Splitter (2 TRS Female to 1 TRRS Male) Compatible for Xbox One, PS4, Smartphone, Laptop to a Double Plugs Gaming Headset Adapter - 30cm/12inch: Electronics

Amazon.com: 3.5mm Headphone Splitter Adapter, MillSO CTIA Audio Splitter (2 TRS Female to 1 TRRS Male) Compatible for Xbox One, PS4, Smartphone, Laptop to a Double Plugs Gaming Headset Adapter - 30cm/12inch: Electronics

www.amazon.com