How can I add custom functions to use within Lenses (UDF)?
When it comes to UDF’s, Lenses allows you to add your functions during the creation of the Docker image to be used. You can also create a Docker image or even a server via a web server. The custom UDFs work for both the Streaming engine and the Snapshot engine. There is more detailed information in the documentation on the modes in which you can work with UDFs. In this link, you can see in the Helm chart where you define the volume mount point for your plugins in Lenses deployed in Kubernetes: https://github.com/lensesio/lenses-helm-charts/blob/release/5.3/charts/lenses/values.yaml#L79
For additional information about the plugins, please check this link: Lenses plugins | Lenses.io Documentation
You can also find more details about UDFs that can be helpful here: User Defined Functions for SQL and Streaming SQL | Lenses.io Documentation