SUMIFS formula help

I am trying to create a formula to sum the total of transactions between two dates and I can’t get it to work. The data needs to come from my referenced subtable. So basically the formula should be like SUMIFS(D21,A21,">=2019/01/01",A21,"<=2019/01/31"). What am I doing wrong? I have tried multiple ways by changing the date format, adding the & symbol, adding seperate cells for the start and end date (so it references A4 and A5 instead of the actual date) Please Help!

Hi there,
Beside creating two reference date fields (e. g. “Start” field to enter the value 2019/01/01, and “End” field to enter the value 2019/01/31. Say the coordinate of “Start” is A4 and “End” is A5, the formula should then be written as SUMIFS(D21,A21,">=A4",A21,"<=A5"), make sure that the field where you apply the formula is a numeric field.