They offer JDBC/ODBC drivers, which should make this relatively easy:
We are also looking for connecting to Databricks SQL Endpoint from Retool.
Hi all, Thanks for requesting this on our forum 
We're tracking requests for a Databricks integration internally and I'll be sure to update this post if we ship a Databricks integration!
How am I able to upvote this? I would love to see native Delta Lake functionality!!
Looking for a direct way to connect to databricks endpoint. Is there a way we can expedite the feature addition?