This seems to be a personal setting on your computer and to resolve it, please follow the steps outlined below:
For Mac OS
Open System Preferences.
Go to Users & Groups.
Choose your nickname on the left.
Choose Login items tab.
Check startup programs you want to remove which should be Postman
Press the โโโ sign below.
Youโre done.
For Windows
Select the Start button, then select Settings > Apps > Startup . Make sure any app you want to run at startup is turned On .
If you donโt see the Startup option in Settings , right-click the Start button, select Task Manager , then select the Startup tab. (If you donโt see the Startup tab, select More details .) Select the app you want to change, then select Enable to run it at startup or Disable so it doesnโt run.