VLAN 1 Name and IP Address

I'm new to Fortinet switching. I created some VLANs in the admin UI, but I don't see VLAN 1 in the list. I assume because that's the default VLAN. I set up a few others and they're good to go. However, I want to nickname VLAN 1 "Data VLAN" and give it an IP address that's in a different subnet than the default gateway. (I did set the default GW already). I tried searching the forums but didn't see where I can configure VLAN 1. Thanks.