Stereo to MacBook Air??

I am attempting to transfer my vinyl records to my MacBook Air. Record player is part of stereo set up containing receiver, CD player and tape deck. I connected to headphone port on receiver with 1/4" to 3.5mm adaptor then ran a 3.5mm line from to Mac Air head phone port. I'm using Audio Hyjack app to record and convert audio. After much messing with the sound preference and audio midi settings was finally able to get the external mic to show as an option for audio input. However it has mono as only option, no stereo! Also tried using USB port as input option using an 3.5mm to USB adaptor, no luck. My question is how do I get the stereo audio into the MacBook Air (2018)??????