Loopback
Loopback is an audio routing and mixing utility available for MacOS created by Rogue Amoeba. Loopback allows you to create a virtual input device, assign sources (such as a physical microphone, audio from chrome, etc), route it as many channels as needed, and then add monitors (headphones, speakers) if needed. Loopback is a great way of getting audio from one program on your computer to another (such as inputting Qlab to zoom). Anywhere where you can configure a microphone input or speaker output can be set to go to a virtual loopback device. It pairs particularly well with audio hijack.
COST:
Free trial with limitations
99USD Perpetual License
Discount with other Rogue Amoeba programs