The launch of the app catalog at the site collection level was a very good decision and brings a lot of benefits. If you want to deploy an app catalog to a site collection, a tenant app catalog must exist. Then you can deploy a new app catalog to a site collection using the following PowerShell command:
<pre><code class="lang-bash">Connect-SPOService -Url https://{tenant}-admin.sharepoint.com -Credential {admin-email-address}

Add-SPOSiteCollectionAppCatalog -Site https://{tenant}.sharepoint.com/{sitecollectionurl}
</code></pre>
For an administrator, it is of course very interesting on which sites an app catalog already exists. Without having a specific request, I recently came across an interesting and hidden list that is located in the Tenant App Catalog. 
The URL to this hidden list is <code>/Lists/SiteCollectionAppCatalogs/</code>. So e.g. <code>https://{tenant}.sharepoint.com/{tenant-app-catalog-site}/Lists/SiteCollectionAppCatalogs/AllItems.aspx</code>
<img src="https://cdn.hashnode.com/res/hashnode/image/upload/v1636101834828/YNDWxI5-g.png" alt="Listview of all site collection urls with app catalog" />
The problem with this list is that it is not updated. That means deleted sites or sites where the URL has been changed are NOT updated/deleted in the list. Not well thought out by Microsoft.
I hope this information helps you as well.

The launch of the app catalog at the site collection level was a very good decision and brings a lot of benefits. If you want to deploy an app catalog to a site collection, a tenant app catalog must exist. Then you can deploy a new app catalog to a site collection using the following PowerShell command:

```bash
Connect-SPOService -Url https://{tenant}-admin.sharepoint.com -Credential {admin-email-address}

Add-SPOSiteCollectionAppCatalog -Site https://{tenant}.sharepoint.com/{sitecollectionurl}
```

For an administrator, it is of course very interesting on which sites an app catalog already exists. Without having a specific request, I recently came across an interesting and hidden list that is located in the Tenant App Catalog. 

The URL to this hidden list is `/Lists/SiteCollectionAppCatalogs/`. So e.g. `https://{tenant}.sharepoint.com/{tenant-app-catalog-site}/Lists/SiteCollectionAppCatalogs/AllItems.aspx`

![Listview of all site collection urls with app catalog](https://cdn.hashnode.com/res/hashnode/image/upload/v1636101834828/YNDWxI5-g.png)

The problem with this list is that it is not updated. That means deleted sites or sites where the URL has been changed are NOT updated/deleted in the list. Not well thought out by Microsoft.

I hope this information helps you as well.


Discover SharePoint site collection app catalogs with Tenant App Catalog URL

How to get all existing SharePoint site collection app catalogs