Creating an Exchange Online Shared Mailbox in Exchange Hybrid

As we are currently running a hybrid Exchange environment, we can't use the Exchange Admin Centre to create a shared mailbox as it won't be accessible. Instead, we need to create a remote shared mailbox in Exchange On-Prem and let the synchronisation process do its work. The process for doing this is as follows:

Log on to one of the Exchange servers - it doesn't matter which one - and start the Exchange Management Shell from the menu.
At the prompt, enter the following command:

New-RemoteMailbox -Shared -Name "{Name}" -Firstname "{FirstName}" -LastName "{LastName}" -UserPrincipalName "{Address}@trafford.gov.uk" -OnPremisesOrganizationalUnit "OU=Mail_Resource_Accounts,OU=User_Accounts,DC=trafford,DC=gov,DC=uk" -RemoteRoutingAddress "{Address}@traffordgovuk.mail.onmicrosoft.com"

Where:
{Name} is the name for the mailbox
{FirstName} and {LastName} will be derived from the name of the mailbox. Either of these commands can be skipped if required
{Address} is the portion of the email address for the mailbox before the @ symbol. For example, if the email address is archive@trafford.gov.uk, then {Address} will be archive
When the command has finished, it should show a message similar to the below:
Run Active Directory Users and Computers (ADUC), ensure you are connected to the trafford.gov.uk domain, navigate to User_Accounts, Mail_Resource_Accounts and locate the account that has been created, which should have the name{Name}. This account will be disabled, do not enable it! Verify that the name and email address are correct, then close ADUC
Log on to the On-Prem Exchange Management Console and search for the new mailbox. Check the email addresses associated with it show SMTP addresses that match the User Principal Name and Remote Routing Address
(Optional) Log on to the Azure AD server TCAZUREAD. Once logged on, open Powershell and enter the following command:

Start-ADSyncSyncCycle -PolicyType Delta

This will force a synchronisation between the domains, which will accelerate the account creation process
This is only necessary if you're in a rush to complete the process. If you're in no hurry, you could wait the 30 minutes for the synchronisation to occur naturally and pick up the process from there
Go back to the Exchange server and enter the following command:

Get-RemoteMailbox "{Name}" | ft DisplayName,PrimarySmtpAddress,RecipientType,Remote*

This should result in something similar to the following:
Start a PowerShell session on your computer, connect to Azure AD and Exchange Online and then run the following command:

Get-Mailbox "{Name}" | ft DisplayName,PrimarySmtpAddress,RecipientType,Remote*

This should display similar to this:
Now, log on to the Exchange Online Management Centre and search for the new mailbox. It should appear as the type SharedMailbox. Check the email addresses have the SMTP entries as in step 5 above
The mailbox is now ready to use. Whilst in the Management Centre, you can set up the required delegations