Recently purchased and have this device connected to my small office land line phone (an older two line cordless Panasonic) https://www.amazon.com/gp/product/B00T45CTKG/ connected to my Windows 10 mic in port. Works great
I’ve tinkered with Audacity a bit and achieved only part of my wants. Ideally, I’d like the recording software to
1- Detect sound then start recording
2- Stop recording after a preset period of silence
3- Auto save the file in a common audio format in a chosen directory
4- Reset to Detect sound then start recording to a new file, not append to the previous
Seems that you need a different kind of recording program.
Have you tried searching Google / Bing / other, for “call recording software”?
Alternatively, a hardware solution may work best - see what features are available on answering machines.
The way that you would do it with Audacity is to record one long track (I wouldn’t recommend going over 12 hours), and then use “Sound Finder” to label the parts that have audio (see: Sound Finder - Audacity Manual), then use “Export Multiple” to export the labeled sections (see: Exporting multiple audio files - Audacity Manual)
I agree with the comment by kozikowski. You do have to consider legalities with recording people. In many places you have to let people first be aware that they are being recorded.