Hi, @iamkratos. That guide is taking about installing a plugin for the CLI tool which means it is quite out of date. That hasn’t been the correct workflow for years.
I believe the issue here is that the Git credential helper is not installed so Git cannot talk to Large Media. This is installed by the Netlify CLI tool. There is troubleshooting guide about this here:
Would you please try the solution in that support guide and let us know if there are any other questions?