Postman is a usefull app to build and test APIs, most commonly installed on ubuntu-like systems via snap. On recent distributions of Linux Mint (20 and above), snap installs are no longer possible. The instructions below show how to install Postman via the terminal.
$ wget https://dl.pstmn.io/download/latest/linux64 -O postman.tar.gz
$ sudo tar -xzf postman.tar.gz -C /opt