```r
union = run_qgis(alg, INPUT = incongr_wgs, INPUT2 = aggzone_wgs, 
                 OUTPUT = file.path(tempdir(), "union.shp"),
                 load_output = TRUE)
#> $`OUTPUT`
#> [1] "C:/Users/geocompr/AppData/Local/Temp/RtmpcJlnUx/union.shp"
```