Hello! Thanks for this question.

You mention sudo so I'm assuming a Unix system (Linux or Mac). It is indeed possible to install GCM on Linux and Mac without requiring root/sudo.

We ship tar.gz files for both platforms that contain the pre-built binaries and don't require root to install.

If you look at the releases page, you'll see the following assets you can download and extract:

gcm-linux_amd64.2.6.1.tar.gz
gcm-osx-x64-2.6.1.tar.gz

You can extract those archives with tar xvf gcm-linux_amd64.2.6.1.tar.gz and then directly configure GCM as your credential helper with ./git-credential-manager configure