How do I create a new Pool and assign an IP to that pool?

Please follow below steps to assign one or more IPs to a pool.

In Netcore Email API user panel, go to 'Dedicated IP' page.
Go to 'Manage IP'.
Mark the checkbox of the IP you wish to select.
Select 'Assign selected IP to' in the first dropdown below your IP list.
Select 'Pool' in the second dropdown. If the pool is not available in 'Manage Pool', then it will be created for you.
Select the pool name you wish to assign the IP, in the third dropdown.
Confirm the selection by pressing 'Apply' button.