Connect-ExchangeOnline
:: Enter the email address to connect with below
$Email = 
$Group = Get-UnifiedGroup -Identity $Email
$GroupId = $Group.ExternalDirectoryObjectId
$Group.ExternalDirectoryObjectId
Remove-Variable Group, GroupId

Import-Module MicrosoftTeams
Connect-MicrosoftTeams
Get-TeamChannel -GroupId $Group.ExternalDirectoryObjectId