SUM based on specific criteria

Hello all, 

I would like to ask you for your help with folowing situation: I have this table:

And I need the SUM of quantity for specific operation, so expected outcome will be in my case:

0901 - 4

0902 - 13

0903 - 9

0990 - 10

I used measuere with CALCULATE( SUM(), GROUPBY()), CALCULATE(SUM(), ALLEXPECT()) but always with the same result:

Any idea how to solve it?

Thanks for your help.

P.