No worries, @ssimara.
Just add the parameter when (re)generating the nodes (see #3), here for example for the PetStore Nodes:
java -jar nodegenerator.jar https://petstore.swagger.io/v2/swagger.json --root-categories "nodegen=NodePit API Generator"
Hint 1: There are plenty more options available. You can list them running the following command:
java -jar nodegenerator.jar
Hint 2: Once generated, you can run the generated script generate.sh in your node directory to re-generate the nodes. All previous parameters are stored in the args file and will be used on regeneration, so you can also add parameters to this file before running generate.sh.
Best regards,
Daniel