you must sign in to view your purchases

Hi MdSaifulIslam1110,

We'll be glad to help. If you need assistance signing in to view your purchases, you can sign in to the App Store on your Mac with the steps outlined in Sign in to the App Store on Mac - Apple Support

"1. In the App Store  on your Mac, click Sign In at the bottom-left corner.

Do any of the following:

• Create an Apple ID (if you don’t already have one): Click Create Apple ID, then follow the onscreen instructions.
• View account settings: Click your name in the bottom-left corner, then click Account Settings.
  • Account information includes your Apple ID, billing information, and the nickname you use when you review apps. You can also view purchases that you’ve hidden."

Cheers.