In my experience with the Splunk add-on,  it is typically used to pull Databricks data into Splunk, not to push.   If the data sets are small then it could probably push as well, but I think you'd have to write some sort of Splunk map loop to issue INSERT statements against Databricks.

It would probably be more manageable to use this approach,  https://github.com/databrickslabs/splunk-integration/blob/master/docs/markdown/Databricks%20-%20Pull....

This may also provide guidance:  https://registry.terraform.io/modules/databricks/examples/databricks/latest/examples/adb-splunk