Create a file named Postman.desktop under ~/Downloads/sfw/Postman/app/resources with below content:
[Desktop Entry] Encoding=UTF-8 Name=Postman Exec=~/Downloads/sfw/Postman/app/Postman %U Icon=~/Downloads/sfw/Postman/app/resources/app/assets/icon.png Terminal=false Type=Application Categories=Development;
Then execute below command to install the Postman.desktop:
zzh@ZZHPC:~/Downloads/sfw/Postman/app/resources$ install -t ~/.local/share/applications/ Postman.desktop
Copied from: https://learning.postman.com/docs/getting-started/installation/installation-and-updates/