sum by category

Thanks for the initial answer, unfortunately I still haven't managed ,I will try to explain again and I have also uploaded a new picture with the result that should be reached, If a certain truck arrived at a certain customer on the same date, then the transaction is considered as one transaction and the amount must be summed up, in any case the amount must be summed up for each truck but as soon as it arrives at the same customer on the same date then the same day must be summed up for that customer, in addition I have to To do this for a group called "menta cust", I have to do the summary once for truck 1, once for truck 2 and once for truck 3, at least show me for truck 1 the rest I will complete, I have the dates in the data file, I don't need to show them in the query, I just want to know the amount for each truck so that I will spread it on the report and it will be visible., thank you very much.