Hi @siforibo ,
You should just be able to use the name of the DataVerse table's Primary Column
Set(idreclamation, Form1.LastSubmit.primaryColumnName)
I notice in your above comment you have a semi-colon ";" in your Set statement, change it to a comma ",".
For testing, you can get rid of the Set statement. Just add a label to your app and for the text property, start typing
Form1.LastSubmit.
This will obviously only work after you have performed a SubmitForm(Form1).
Once you add that period, the formula bar should suggest to you all of the field names that are available to you, you can try them out until you get the one you want. Then you know the LastSubmit is working, and you can paste that into your Set statement.
The "variable type is not compatible with value types elsewhere in your application" just means that here you are trying to assign the variable with e.g. an integer but elsewhere you have assigned it e.g. a record. But don't worry about that too much until you have finished getting rid of the first problem.