Pushing to new GitHub organisations gets 403 error

I installed GitKraken in a VM and in the GitHub authorisation process I had to indicate when organisations it could access. The new repo had a red Cross against it. I selected it, to allow GitKraken access to that organisation. GitKraken was then able to push to the new repo.

I then received an email telling me the GitHub authorisation had been added. It included a link to this page https://github.com/settings/connections/applications/

From that page I was able to view authorised OAuth apps. SmartGit (my normal Git client was listed). When I went into the page for that app, I saw it wasn't allowed access to my new organisation. I authorised access.

From that point on, I was able to push from either SmartGit or the command-line.

I had the same issue with SourceTree.

HTTP Error Code 403 and no access, but using GitHub.com (web) worked without any issues. As pointed out already, the third party application has no access.

Ensure that your Organization has the third-party app approved (SourceTree, GitKraken, etc.) https://github.com/organizations/%ORGANIZATION_NAME%/settings/oauth_application_policy

• You can approve the app by first connecting it with your account and then going to https://github.com/settings/connections/applications/
• From there, click on the name (link) and the application detailsv will be shown. -At the bottom, you'll see your Organizations and you can approve it ❤️