How to add simple counter field

[Yossi_Oulu]

Hi,
Im adding multiple rows to a table via the appsheet api.
I would like to update a column with counter of the current row. (E.g. 1, 2, 3,…) how to do it?

If I use max(…)+1 it does not work correctly as the rows hasn’t written yet so few rows gets the same number.
The table is in excel.
This is what im trying to get
1 itemx
2 itemy
3 itemz
Thanks