I have a project which I want to use a different user.name (leeyuiwah), which is different to the global value leeyuiwah-sl), to talk to a certain repo in github.com.  I have already updated the project's .git/config but then my command got this error
$ git push -u origin master
remote: Permission to leeyuiwah/brti.git denied to leeyuiwah-sl.
fatal: unable to access 'https://github.com/leeyuiwah/brti.git/': The 
requested URL returned error: 403
I ran this and the settings seem to be right:
$ git config --list | grep -E -e "user.*name"
credential.username=leeyuiwah
user.name=leeyuiwah
But then I realized I had a config file used by SourceTree that stored the wrong name
$ find . -type f | xargs grep leeyuiwah-sl
./.git/sourcetreeconfig.json:      "Username": "leeyuiwah-sl",
So I think I could just edit that JSON file. I did that but it did not help.
Now I am stuck. Any suggestion?
Update
More info as per comment:
$ git remote show origin
* remote origin
  Fetch URL: https://github.com/leeyuiwah/brti.git
  Push  URL: https://github.com/leeyuiwah/brti.git
  HEAD branch: (unknown)
And
$ git config --list --show-origin | grep leeyuiwah
file:.git/config        
remote.origin.url=https://github.com/leeyuiwah/brti.git
file:.git/config        credential.username=leeyuiwah
file:.git/config        user.name=leeyuiwah
file:.git/config        user.email=leeyuiwah@gmail.com