You're going to have to install something, macOS can't do this on its own - in fact, as far as I'm aware, no OS can do this on its own; they all need some kind of routing utility.
I haven't used all of these, so I can't list them in any kind of 'best' order.
My personal favourite & the only one I really use these days is…
Loopback - expensive for a one-trick pony, but like all things from Rogue Amoeba, it "just works".
To make this list more comprehensive, Rogue Amoeba make several routing apps for slightly different purposes. Also check out Audio Hijack and SoundSource
All below are ones I'm aware of but haven't used. They're mainly freeware/shareware/donationware
iShowU Audio Capture
iShowU Audio Capture is an extension to OS X used by iShowU Studio and iShowU Instant to record audio from your computer. This new-and-improved audio driver replaces Soundflower and provides a bunch of new features and improvements in order to make recording audio more stable and easy to do.
Jack Audio Connection Kit
Open source routing.
VB-CABLE Virtual Audio Device
New to macOS, has been around a while on Windows.
VB-CABLE is a virtual audio device working as virtual audio cable. All audio coming in the CABLE input is simply forwarded to the CABLE output.
New kid on the block.
BlackHole is an open source virtual audio driver that allows applications to pass audio to other applications with zero additional latency.
Sound Siphon Paid.
Seems to be a straight copy of Loopback.
The original… updated for Catalina.
MacOS system extension that allows applications to pass audio to other >applications. Soundflower works on macOS Catalina.
Soundflower used to be the go-to routing app for OS X but got less reliable over time. It was passed around between new owners for some time - initially Cycling '74, then Rogue Amoeba took a caretaker role for a while. It's now back in the hands of its original creator, Matt Ingalls. One essential part is missing compared to early versions, Soundflowerbed, which was the vital routing component. I haven't used it since the early days, when it was tough to set up but easy to work with once you had. Many people seem to struggle with the setup.