Why we can't search for safari extensions on app store?

It is the app that contains the Safari Extension. You download the app from the App Store and then you can install the Safari Extension that is bundled in the App. There is no such thing as downloading an Extension without the app where it resides in the bundle. When the app receives an update through the normal update process, then it is the Extension that also receives the update. Deleting the app will also delete the Extension.

You see the app as well in some cases because the extension is bundled with the app.

You can let Apple know what you'd like to see here:

Product Feedback - Apple

And since your tagline shows a MacBook Air, all you need to do is choose Safari Extensions in the Safari pull down menu and it will take you directly to the Extensions offered in the App Store for you to download. You may find that easier than searching "Safari Extensions" in the App Store because they are categorized by the extension type you are looking for.

yasinnx wrote:

Can you explain the search and results

Mac Jim ID already explained it. The extension is downloaded with the app.

This is a screenshot of the page from the first app in your picture:

yasinnx wrote:

Why we can't search for safari extensions on app store?

I don't know why you can't. I can, though. I type "safari extension" into the search bar, and extensions appear. How are you trying to do it?

yasinnx wrote:

I just want to find the extension I type, I don't want to see whatsapp messanger for vpn search.

Enter the name of the Extension you want to download. Typing "Safari Extension VPN" is going to list all that are related to those search terms. In fact most VPN's do not even include a Safari Extension, they run on startup so you can use any browser you wish. If you just want to search for a VPN, then that is what you should enter in your search term.

yasinnx wrote:

I just want to find the extension I type, I don't want to see whatsapp messanger for vpn search.

As noted above, tell Apple what you'd like to see.

yasinnx wrote:

I sent but if they didn't build a system like chrome web store, they won't build it soon

I'm pretty sure Apple doesn't want to be Alphabet. And they definitely don't seem to want Safari to be Chrome, something for which I am grateful.