I need to store the updated value from the IG in the P12_EMPNO page element.
To do this, use this code in DA --- > Run Javascript code
var changedValue = apex.item("N001").getValue();
apex.item("P12_EMPNO").setValue(changedValue);
But the value is not stored in the P12_EMPNO page item.
Note: I only need to save the value I'm updating...
For example: If the value 1003 (already present) is updated to 1004 (update value), I need to store 1004 in P12_EMPNO.
See page 12
Environment:https://apex.oracle.com/pls/apex/
Workspace: shajin_wk
username: Test
pwd: Test@123

Looking at your application, the reason you're getting the error is because of the following attributes in the page process:
Note that you can use apex_debug to log entries that can be viewed in debug mode.