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 Public Folders
On the left hand side, click on public folders.
4. Create a public folder mailbox
On the top, click on public folder mailbox and then click the + button to add a new mailbox.