Q:

How to enable ADAL(Modern Authentication) for Skype for Business Online?

A:

To enable ADAL(Modern Authentication) for Skype for Business Online, please follow these steps below.

※These steps can only be executed by Office365 Administrator

0) Please install 「PowerShell」 3.0 or later version.

https://docs.microsoft.com/en-us/powershell/scripting/windows-powershell/install/installing-windows-powershell?view=powershell-5.1

1) Please install「Teams PowerShell module」from the URL below.

https://docs.microsoft.com/en-us/skypeforbusiness/set-up-your-computer-for-windows-powershell/download-and-install-the-skype-for-business-online-connector

2) Run PowerShell as an administrator, and execute the commands below to connect to Skype for Business Online.

Import-Module MicrosoftTeams
$userCredential = Get-Credential  ※You will need to login as Office365 Admin.
Connect-MicrosoftTeams -Credential $userCredential

3) Use the command to ensure the successful connection to Skype for Business Online.

Get-Module

You will expect the results below:

ModuleType Name                 ExportedCommands
---------- ----                 ----------------
Manifest   Microsoft.PowerS...  {Add-Computer, Add-Content, A...}
Script     tmp_5astd3uh.m5v     {Disable-CsMeetingRoom, Enabl...}

※Row number will be decided by each environment situation.

3) Execute the command to enable  ADAL(Modern Authentication) for Skype for Business Online.

Set-CsOAuthConfiguration -ClientAdalAuthOverride Allowed

4) Execute the command to ensure you have enabled ADAL(Modern Authentication) for Skype for Business Online.

Get-CsOAuthConfiguration

If ClientAdalAuthOverride field becomes "Allowed", you have completed the activation.

※Reference

https://social.technet.microsoft.com/wiki/contents/articles/34339.skype-for-business-online-enable-your-tenant-for-modern-authentication.aspx

https://technet.microsoft.com/en-us/library/dn362795.aspx