1.Install Mac OSX 11 driver v1.7.0 from official website.

(https://www.aten.com/global/en/products/usb-&-thunderbolt/usb-converters/uc232a/)

(ls /dev/tty.usb*)

For example, it's tty.usbserial-130.

3.Type in "screen /dev/tty.usbserial-130 19200 8N1" then it's able to send commands to the serial device that UC232A connected to.

Refer to attached file for more details.