Explanation:

Box 1: Set-CalendarProcessing
Allow calendar invite processing for third-party meetings
The first thing you need to do to enable a one-touch join experience from Team Rooms is set the calendar processing rules for the device's Exchange Online room mailbox. The room mailbox needs to allow external meetings and keep the message body and subject so it can see the URL needed to join the third-party meeting.
To set these room mailbox options using the Set-CalendarProcessing cmdlet, do the following:
1. Connect to Exchange Online PowerShell.
2. Get the User Principal Name (UPN) of the room mailbox if you don't know it by running the following command:
Get-Mailbox | Where {$_.RoomMailboxAccountEnabled -eq $True} | Format-Table Name, UserPrincipalName
3. Find the name of the room mailbox associated with your Teams Rooms device and make note of its UPN.
4. After you find the room mailbox's UPN, run the following command. Replace <UserPrincipalName> with the room mailbox's UPN:
Set-CalendarProcessing <UserPrincipalName> -ProcessExternalMeetingMessages $True -DeleteComments $ Box 2: -ProcessExternalMeetingMessages Reference:
https://learn.microsoft.com/en-us/microsoftteams/rooms/third-party-join#step-3a-enable-third-party-meetings-on