ffmpeg – Feed result of complex filter to a simple filter to another in FFmeg

so i was trying to stack a few images using ffmpeg, but i noticed the output was the wrong orientation, so i attempted to correct that using the transpose filter, leading me to this command:

ffmpeg -i a.jpg -i b.jpg -i c.jpg -i d.jpg -filter_complex "[0][1][2][3]vstack=inputs=4" -vf "transpose=2" therta.webp

but i get

Filtergraph 'transpose=2' was specified for a stream fed from a complex filtergraph. Simple and complex filtering cannot be used together for the same stream.

how do you fid the outpot of a filter to another one then?