Hi Shum,

You will observe that the implemented Add Row logic uses the ListInsert client action with Position value 0 to add a new row at the start of the table. 

For your requirement, to add a new row after a specific existing row, you can introduce an input parameter called index, to the AddNewRow screen action and pass it to the ListInsert client action element's Position property.

ListInsert client action inserts an element in a specific position (based on the position property value) of a list.

I hope this helps you!

Kind regards,

Benjith Sam