Inside the dxvk-tools directory, run:
./updxvk build
Inside the dxvk-tools directory, run:
./upvkd3d-proton build
Still inside the dxvk-tools directory, after you ran the command above, run:
./updxvk proton-tkg
DXVK files will be copied in a folder next to proton-tkg script, ready for building.
You'll find more details on the various functions (such as installation-related ones) of these scripts right inside them.