Make sure your workflow has an output variable called resourceNames of type Array/string.
Then in your scriptable task:
var resourceNames = inputProperties.resourceNames; resourceNames[0] = 'newName';
Obviously this is a super simplistic example, remembering that this workflow will run once per compute stack on the blueprint. So if your count setting for the stack is greater than 1 you'll need to generate X number of names.
You can also do it with ABX if you don't have a specific need to use vRO. Projects also offer a naming template function though it is more limited and specific to each instance of vRA and each project.