Basta fechar a janela.
As for your connection to Office 365, although there’s a Connect-MsolService cmdlet, there’s no corresponding Disconnect-MsolService cmdlet. So for Office 365, just close the Windows PowerShell window. (Nevertheless, it’s still a good idea to do this last so you can properly disconnect from SharePoint Online, Skype for Business Online, Exchange Online, and the Security & Compliance Center.)