解決したいこと

今Djangoを
https://tutorial.djangogirls.org/ja/deploy/
で勉強しているのですが、Gitから
git push -u origin masterを押しても

毎回

: The requested URL returned error: 403
が表示されてしまいます。

何とか解決方法を教えて頂きたいです。

ちなみにこんな感じで進めてました。

(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls % git config --global user.email you@example.com
(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls % git status
On branch master

No commits yet

Untracked files:
(use "git add ..." to include in what will be committed)
.gitignore
blog/
manage.py
mysite/
requirements.txt

nothing added to commit but untracked files present (use "git add" to track)
(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls % git add --all .
(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls % git commit -m "My Django Girls app, first commit"
[master (root-commit) 20fda7a] My Django Girls app, first commit
15 files changed, 243 insertions(+)
create mode 100644 .gitignore
create mode 100644 blog/init.py
create mode 100644 blog/admin.py
create mode 100644 blog/apps.py
create mode 100644 blog/migrations/0001_initial.py
create mode 100644 blog/migrations/init.py
create mode 100644 blog/models.py
create mode 100644 blog/tests.py
create mode 100644 blog/views.py
create mode 100755 manage.py
create mode 100644 mysite/init.py
create mode 100644 mysite/settings.py
create mode 100644 mysite/urls.py
create mode 100644 mysite/wsgi.py
create mode 100644 requirements.txt
(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls % git remote add origin https://github.com/MASA-study/my-first-blog.git
(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls % git push -u origin master
remote: Permission to MASA-study/my-first-blog.git denied to Masataka-Fukuhara.
fatal: unable to access 'https://github.com/MASA-study/my-first-blog.git/': The requested URL returned error: 403
(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls % git remote add origin https://github.com/Masataka-Fukuhara/my-first-blog.git
fatal: remote origin already exists.
(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls % git push -u origin master
remote: Permission to MASA-study/my-first-blog.git denied to Masataka-Fukuhara.
fatal: unable to access 'https://github.com/MASA-study/my-first-blog.git/': The requested URL returned error: 403

(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls % git push -u origin master

remote: Permission to MASA-study/my-first-blog.git denied to Masataka-Fukuhara.
fatal: unable to access 'https://github.com/MASA-study/my-first-blog.git/': The requested URL returned error: 403
(myvenv) massattack@fukuhara-masataka-no-Mac-Pro djangogirls %

自分で試したこと

GitやDjangogirlsのファイルを全て消して何度か
Djangoのインストール
https://tutorial.djangogirls.org/ja/django_installation/
これではじめてみましたが、やはり同じところで同じ現象がおきる状態です。

皆様何卒宜しくおねがいいたします。