@BhargaviE9056

Here’s the thing: in Constellation you won’t get Pre/Post Data Transform on a modal view, by design, so the tab you’re looking for doesn’t appear on the data object view used by the Add-row modal. Use pyDefault in the data object’s class to set pre-open defaults; Constellation calls that when a new embedded row page is created. For “post,” don’t hunt inside the modal—wire it to the action that commits the row: primary button = Save (or save via the savable Data Page) → Run Data Transform → Refresh the table. If the list is an associated data relationship, set Create/Save data transforms on that relationship so they execute on row create/save. If you need logic before opening, replace OOTB Add with a button that runs a Data Transform, then opens the modal. If you only need defaulting, pyDefault on the embedded page class is the clean path and works across versions.  If none of the above fits, move the post logic to the case step’s post-processing (DT) that runs right after the modal’s submit triggers the save. Finally, keep your Constellation 23.1.x patches current; some action options show up only after recent updates.