How to identify Sharepoint Online sites which belongs to Teams private channels

In MS Teams team owner may create private channels: only members of these channels will have access to these channels. What happens under the hood is that for each private channel Teams creates separate SPO site collection with own permissions. E.g. if we have team with 2 private channels channel1 and channel2:

it will create 2 SPO sites with the following titles:

• {team name} - channel1
• {team name} - channel2
  

If we will visit these sites in browser we will notice that there will be teams icon near site title and "Private channel | Internal" site classification label:

How we may identify such SPO sites which correspond to teams private channels? E.g. if want to fetch all such sites via search.

At first I tried to check web property bag of these sites because this is how we may identify that site belongs to O365 group (see Fetch Sharepoint Online sites associated with O365 groups via Sharepoint Search KQL) but didn't find anything there. The I used Sharepoint Search Query Tool and found that these sites have specific WebTemplate = TEAMCHANNEL:

So in order to identify SPO sites which correspond to teams private channels we may use the following KQL:

WebTemplate:TEAMCHANNEL

It will return all sites for teams private channels.