How to resolve the missing OpenMV SDK error

OpenMV Boards
1

Why, when I compile the source code and execute the command make -j$(nproc) TARGET=OPENMV4P, does it prompt:
make -j$(nproc) TARGET=OPENMV4P Makefile:38: *** OpenMV SDK not found. Run 'make sdk' to install it.?

2

Run `make sdk` to install it.