Here are my 2 cents.
I got it working on my Macbook Pro 2019 and Macbook Air M1 2020.
First, install GitHub - WCHSoftGroup/ch34xser_macos: MacOS USB driver for USB to serial chip ch340, ch341, ch342, ch343, ch344, ch9101, ch9102, ch9103, etc
Follow the readme very carefully.
When the Chinese window appears during the installation, go to security settings and allow extension.
Restart your Mac and connect the device.
You should see something like /dev/tty.wchusbserial51850141401
If you see /dev/cu.usbmodem52D50033451 instead of /dev/tty.wch* then the driver installation failed.
You have to uninstall the driver, reboot, and install again, following the exact steps in the readme.
Also, pay attention to this article when the Chinese window appears, you have to allow the extension first.
https://developer.apple.com/library/content/technotes/tn2459/_index.html
If the driver installation succeeds, you should see something like:
/dev/tty.usbmodem51850141401 - This does not work.
/dev/tty.wchusbserial51850141401 and that works OK.
Hope someone finds this helpful.