I forget this every time I reset my password…
(Get-Credential).Password | ConvertFrom-SecureString | Out-File "C:\Scripts\365SecureString.txt"
Using it:
$pass = cat "C:\Scripts\365securestring.txt" | convertto-securestring $mycred_online = new-object -typename System.Management.Automation.PSCredential -argumentlist "UserAccount@contoso.com",$pass $mycred = new-object -typename System.Management.Automation.PSCredential -argumentlist "UserAccount",$pass