So those fields are populated via the Campaign Attribution Enrichment, which parses utm parameters according to what you configure (or just the standard defaults if you don’t specify).
The reason you’re getting errors in using that schema specifically because it’s the schema for the configuration, rather than the event itself.
If you need to attach this data separately as a context it is possible to do so using a custom context and schema you define yourself - however I’m guessing that the standard way of capturing this data via utm parameters is what you’re really after.