Could you please share a small sample of “fake” data replicating your dataset for this table (10-12 rows).
If you can also include an screenshot to understand on each cell what is the meaning of each value? E.g. crated_at=May/Send_date=Jul2021, what is the total at that point?
Peter is correct that percentOfTotal currently doesnt support distinct counts, however you could compute your own percent of total with your own numerator and denominator (where we will use an LAC-A function in the denominator to compute it at a different level).