Unable to access button in child table

I’m trying to access a button docfield in child table. Can anyone tell me how to access it ?

If the button was a part of the main doctype, I could have used
cur_frm.cscript.button_name but I am unable to find a way for the child docfield.

@mr-karan, Try with this syntax -

frappe.ui.form.on("Child Table Name", "approve", function(frm, cdt, cdn) {
      // Your Code

worked, thanks @priya_s