JavaScript API Version 4x - Advanced Data Editor - Create a Sequential Unique ID Number when adding new feature?

[IanPeebles]

Hello everyone!  Looking to create a sequential ID number in the advanced data editor form when a new feature is added.  For example, if the unique ID (ASSETID) is NULL when added, I want to look at the latest unique ID number assigned (example: 50000), then add a + 1.  The unique ID number would be 50001.

Here is an example of the data editor form I have put together:

In my particular case, a new feature has been added, but I want the Facility ID to be populated with the latest sequential number (based on Facility ID).

Is this possible with the 4x API?

Any guidance will be greatly appreciated.

Thank you!

Ian