weex-toolkitのインストールができません

タイトル通りです。weexを使いたいのですが

-bash: weex: command not found

と表示されます。
インストールができない原因がわからないので、ご教授お願いします。

環境

node.jsのバージョン

v10.13.0

mpmのバージョン

6.4.1

試したこと

ライブラリのインストール

npm install -g weex-toolkit

インストール後のコマンド

npm WARN read-shrinkwrap This version of npm is compatible with lockfileVersion@1, but npm-shrinkwrap.json was generated for lockfileVersion@0. I'll try to do my best with it!
npm WARN read-shrinkwrap This version of npm is compatible with lockfileVersion@1, but npm-shrinkwrap.json was generated for lockfileVersion@0. I'll try to do my best with it!
npm WARN read-shrinkwrap This version of npm is compatible with lockfileVersion@1, but npm-shrinkwrap.json was generated for lockfileVersion@0. I'll try to do my best with it!
npm WARN checkPermissions Missing write access to /Users/komei/.npm-global/lib/node_modules/weex-toolkit
npm WARN checkPermissions Missing write access to /Users/komei/.npm-global/lib/node_modules/weex-toolkit/node_modules/weex-builder/node_modules/fsevents/node_modules
npm WARN checkPermissions Missing write access to /Users/komei/.npm-global/lib/node_modules/weex-toolkit/node_modules/weex-previewer/node_modules/weex-builder/node_modules/fsevents/node_modules
npm ERR! path /Users/komei/.npm-global/lib/node_modules/weex-toolkit
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall access
npm ERR! Error: EACCES: permission denied, access '/Users/komei/.npm-global/lib/node_modules/weex-toolkit'
npm ERR!  { [Error: EACCES: permission denied, access '/Users/komei/.npm-global/lib/node_modules/weex-toolkit']
npm ERR!   stack:
npm ERR!    'Error: EACCES: permission denied, access \'/Users/komei/.npm-global/lib/node_modules/weex-toolkit\'',
npm ERR!   errno: -13,
npm ERR!   code: 'EACCES',
npm ERR!   syscall: 'access',
npm ERR!   path: '/Users/komei/.npm-global/lib/node_modules/weex-toolkit' }
npm ERR! 
npm ERR! The operation was rejected by your operating system.
npm ERR! It is likely you do not have the permissions to access this file as the current user
npm ERR! 
npm ERR! If you believe this might be a permissions issue, please double-check the
npm ERR! permissions of the file and its containing directories, or try running
npm ERR! the command again as root/Administrator (though this is not recommended).

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/username/.npm/_logs/2018-11-22T17_09_14_213Z-debug.log