Attempting to Create Shared Contact Groups

rsmereka Shared mailboxes are useful if you do not want the sent to multiple mailboxes or you would like all replies to the messages to be from the same email address.
A distribution list on the other hand send emails addressed to it to the individual users' mailboxes. Users can be assigned permission to manage the list so they can add and remove members and you can manage who can send email to the distribution lists. 
Another benefit of distribution list is that I believe there is a limit on the number of share mailboxes but not on the number of distribution lists as they use fewer system resources.
This link provides more information about distribution lists including how to add them in PowerShell. https://docs.microsoft.com/en-us/exchange/recipients-in-exchange-online/manage-distribution-groups/manage-distribution-groups