How to detect duplicated data on Appsheet when user open screen at the same time

[Nattakarn_Girl]

My Appsheet is connected with Google Sheet. I tried to protect duplicated data in Appsheet but

the result isn't good. My key is "Delivery No. = D20220518 and D20220517 ( Auto-generated by Concatenated )

      I have a problem with users recording duplicated data to appointments at the same time ( the detail on my picture ) I figure out that they are opening the screen at the same time ( I saw the data that they logged in on 24/1/2022 on 11.01-11.07 am.) when the first person accepted data, the record will save in google sheet. when the second person accepted data, the record will add a row and save it in different Delivery No. Could you help me find a way to detect duplicated data? please.