Finding the correct 'row ID'

My approach would be to assign a variable such as app variable foundRowNum to the find first occurrence of block to search the list of values in the email column for the user’s email address. That block returns a 0 if nothing is found and an integer representing the row number where it’s first found in the column if it does find it. So you can use the result in an if/else block to say if that variable is greater than zero, update the value in row id [app variable foundRowNum] … else create row.