To install the latest version of the Postman desktop app, you need to install it via the Snap using the following commands.

Install Postman in Debian and Ubuntu

$ sudo apt update
$ sudo apt install snapd
$ sudo snap install postman

Install Postman in Linux Mint

$ sudo rm /etc/apt/preferences.d/nosnap.pref
$ sudo apt update
$ sudo apt install snapd
$ sudo snap install postman

Install Postman in Fedora Linux

$ sudo dnf install snapd
$ sudo ln -s /var/lib/snapd/snap /snap
$ sudo snap install postman


Download Postman-linux-x64-7.32.0.tar.gz files from postman site

$ cd Downloads/
$ tar -xzf Postman-linux-x64-7.32.0.tar.gz
$ sudo mkdir -p /opt/apps/
$ sudo cp -R Postman /opt/apps/
$ sudo ln -s /opt/apps/Postman/Postman /usr/local/bin/postman
$ postman

To start the app from a launcher icon, you need to create a .desktop file (a shortcut that is used to launch an application in Linux) for Postman desktop app and save it in the following location.

$ sudo vim /usr/share/applications/postman.desktop

Then copy and paste the following configurations in it (ensure that the file paths are correct depending on where you extracted the files):

[Desktop Entry]
Type=Application
Name=Postman
Icon=/opt/apps/Postman/app/resources/app/assets/icon.png
Exec="/opt/apps/Postman/Postman"
Comment=Postman Desktop App
Categories=Development;Code;

Save the file and close it.

Source - https://www.tecmint.com/install-postman-on-linux-desktop/