It seems you are using qvina which doesn't take --input flag so instead try this

vina_split out.pdbqt

or if you have AutoDock Vina installed in a folder

cd Vina_installation_dir

dir

and look for

vina_split.exe

because the way you installed it matters here (classic vs modern) since vina_split might be py script (in that case previous cmd would work) or as .exe file. If .exe is found, try

vina_split.exe --input out.pdbqt

Or you may try this instead

vina --receptor receptor.pdbqt --ligand ligand.pdbqt --config config.txt --split_out