Domain not showing when trying to set up nameservers in reseller panel

[Will Case]

I am trying to set my nameservers in the reseller panel and in the drop down box where it says, "with 2 selected IP's" and I set the nameservers to ns1 and ns2, but in the drop down box, there is no domain to add the nameservers.
How do I fix this?
I already have A records set for nameservers. but I think I need the nameservers set in the reseller panel for when I add customers.