2nd NVA creation on Existing VNET

[aravind365]

Hello, I am new to BICEP. I have created an NVA in a new VNET with 3 subnets and associated with Route tables, 3 NICs and associated to the NVA/VM, PIPs etc.
When i want to create a 2nd NVA, it is trying to delete off the existing subnets that are in use already and erroring. Is the solution to add on extra resources to the code along with all the existing resources so it creates the delta ? Or is there a way to check 'if exists' for each resource ? Many thanks !