Hello, I would like some help installing sqlite3 on this tutorial.

λ gem install sqlite3
Temporarily enhancing PATH to include DevKit...
Building native extensions.  This could take a while...
ERROR:  Error installing sqlite3:
        ERROR: Failed to build gem native extension.

    C:/Ruby21/bin/ruby.exe extconf.rb
checking for sqlite3.h... no
sqlite3.h is missing. Install SQLite3 from http://www.sqlite.org/ first.
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=C:/Ruby21/bin/ruby
        --with-sqlite3-dir
        --without-sqlite3-dir
        --with-sqlite3-include
        --without-sqlite3-include=${sqlite3-dir}/include
        --with-sqlite3-lib
        --without-sqlite3-lib=${sqlite3-dir}/lib
        --enable-local
        --disable-local

extconf failed, exit code 1

Gem files will remain installed in C:/Ruby21/lib/ruby/gems/2.1.0/gems/sqlite3-1.3.9 for inspection.
Results logged to C:/Ruby21/lib/ruby/gems/2.1.0/extensions/x64-mingw32/2.1.0/sqlite3-1.3.9/gem_make.out