You don’t need an Azure subscription to revoke a user session. Also, note that the Azure AD PowerShell module is being deprecated. So it’s better to switch to Microsoft Graph PowerShell.
- Install and connect to Microsoft Graph PowerShell.
https://m365scripts.com/microsoft365/connect-to-microsoft-graph-powershell/ - Then run the following cmdlet to revoke user sessions:
Revoke-MgUserSignInSession -UserId <userid>