CoolTerm is a simple serial-port terminal application (no terminal emulation) that is geared towards hobbyists and professionals with a need to exchange data with hardware connected to serial ports such as servo controllers, robotic kits, GPS receivers, microcontrollers, etc.
Here are options for Mac users: CoolTerm. We made a shortlist of some Mac serial port monitors. To exclude these issues, you need to have a USB-to-serial connector and any of the following utilities. During establishing the serial connection on Mac OS, you might face such troubles as an absence of physical COM port and handy software. The user can choose other shells available with macOS, such as the Korn.
As a terminal emulator, the application provides text-based access to the operating system, in contrast to the mostly graphical nature of the user experience of macOS, by providing a command line interface to the operating system when used in conjunction with a Unix shell, such as zsh (the default shell in macOS Catalina). You can also try to add root permissions to your user in /etc/sudoers # root and users in group wheel can run anything on any machine as any user root ALL = (ALL) ALL%admin ALL = (ALL) ALL youruserhere ALL = (ALL) ALL. Try launching your server as root user (with sudo), or try to use a port above 1024. On Mac ports below 1024 can only be bound by the root user.