Hi @David Hadaller, to tweak a connector you need to:
• Fork our repo
• Build the connector locally (check readme file of the connector)
• Make the change you need
• Rebuild the connector, and test is out on a local airbyte instnace
• Open a PR on our repo and our team will review and merge your contribution
About the code itself, if custom attributes are missing fields from an existing stream you need to update the stream's schema to add your field. If custom attributes are a dedicated okta api endpoint, you'll need to code a new stream and declare its schema.