Generate a request asking your upstream project to pull changes into their tree. The request, printed to the standard output, begins with the branch description, summarizes the changes and indicates from where they can be pulled.
The upstream project is expected to have the commit named by <start> and the output asks it to integrate the changes you made since that commit, up to the commit named by <end>, by visiting the repository named by <url>.
Imagine that you built your work on your master branch on top of the v1.0 release, and want it to be integrated to the project. First you push that change to your public repository for others to see:
git push https://git.ko.xz/project master
Then, you run this command:
git request-pull v1.0 https://git.ko.xz/project master
which will produce a request to the upstream, summarizing the changes between the v1.0 release and your master, to pull it from your public repository.
If you pushed your change to a branch whose name is different from the one you have locally, e.g.
git push https://git.ko.xz/project master:for-linus
then you can ask that to be pulled with
git request-pull v1.0 https://git.ko.xz/project master:for-linus