Hi! please get used to work with CLI (Web based interface is mostly to show you some settings instead of permitting you to modify them).
@mg14 wrote: the vlan I need to create is similar to vlan 9 in the attached image. It has Trk1 tagged.
VLAN 9 exists and logical interface Trk1 (aggregation of some physical ports) was made tagged member of that VLAN id.
To create a new VLAN - say you need VLAN id 16 - use the CLI command (config mode):
vlan 16
name <place-a-descripiton-of-this-vlan-here>
exit
it enters you in the VLAN 16 context (from which you can exit with the command exit).
To tag Trk1 with VLAN 16, inside the VLAN 16 context simply:
vlan 16
tagged trk1
exit
write memory (to save)
Done.
The point is: you will need also some access ports as untagged members of that new VLAN, isn't it? otherwise why transport it over the Trk1 interface?
To see the VLANs membership of a particular physical port/logical interface use:
show vlan port <port-id>/<trk-id> details