Set-ExecutionPolicy Remotesigned
Install-Module -Name ExchangeOnlineManagement -RequiredVersion 3.5.0
Import-Module ExchangeOnlineManagement
Connect-ExchangeOnline -UserPrincipalName john.doe@example.com
Set-Mailbox john.doe@example.com -ProhibitSendQuota 19GB -ProhibitSendReceiveQuota 20GB -IssueWarningQuota 18GB
Get-Mailbox <User ID> | Select *quota*