rpi3 bitcoin full node missing wallet commands
The instructions you're linking to include the line

./configure CPPFLAGS="-I/usr/local/BerkeleyDB.4.8/include -O2" LDFLAGS="-L/usr/local/BerkeleyDB.4.8/lib" --disable-wallet


The --disable-wallet in that line (surprise!) disables the wallet functionality, making the node purely act as a P2P participant.

If you want a wallet, you need to configure enabling the wallet support.