Has anyone used Other Attributes: (optional) Example: onkeyup="" onblur="" at the bottom of a custom field to do anything? I’m looking at trying to use this as a typeahead to find street name from a custom table I’ve added in the MySQL db that WP uses. I believe I need to use jquery & Ajax along with a php function. I can’t find any messages on this forum which is remotely close to what I’m attempting.
Thanks!
Jim
Disclaimer: I have not used this feature…sorry.
Having said that…
You seem like a techie. Why not do a dummy run with the onblur with a simple popup to test if it works. Then go from there.
Keep in mind that should probably test within a GB block as well as a classic block AND a classic page to make sure there is no collision between the s2member JS and the core JS. S2member is pre-gutenberg where core JS was simple. In the GB world, core JS is quite sophisticated.
Thank you for that information and will march forward to areas I have not been to… 
I had hoped to find some documentation to get started, but there doesn’t seem to be anything about this area. I’ll write something up when I get this figured out.
While I could put the lists (2) into a dropdown menus, one has 3000 elements and a little too large. I may do that now and work on a type-ahead method for the future.
Thanks!
You can use a scrolling list see https://stackoverflow.com/questions/21998679/css-how-to-make-scrollable-list