ACTION Fill a specific cell in another table

[THTH1]

Hi everybody,

I am new to AppSheet and I am still learning. I am moving forward with my App but I am sometimes stuck for hours on the same issue. Even by looking for solutions around the web …

Here is an issue I’ve been dealing with:

I need 1 cell (from a reference table) to get the row number of the form the user is filling.
To do that, I created an action “When user complete this cell in the form, then send the row number to the cell in the reference table”.

But everything I tried didn’t work. Both on the action trigger side (when user complete this cell in the form) and the action itself (send the row number to the cell in the reference table).

It would be awesome to have some help from you, dear community.

Best regards,
Arnaud