qgis

I have the following situation: two layers that I want to intersect. The first layer has polygons over agricultural areas (blue polygons). The second one is the Study area (green polygon). I want to use the "Study area" layer to complete the blank spaces of the first one:

I am trying with intersect but it is not working.

Edit to reply the answer

I have tried your option but I don't have the expected results. Both layers have the same projection

Second edit: