1. Open the EAC
Click on start and then expand Exchange Server 2016 and click on Exchange Admin Center.
2. Login to the EAC
If you have a certificate warning, click yes to continue and then enter the credentials to login and press enter.
3. Click on Servers
On the left hand side, click on Servers.
4. Double click a server
Click on Unified Messaging tab in the middle and see the warning that the command does not exist as this is a bug in Exchange 2019.