How to pass the equivalent of git push -o <string>?

[MatejLach]

On the Git CLI, I can use git push -o <option> for example git push -o merge_request.create to supply string options with push that are then processed on the server by i.e. the post-receive hook to perform additional actions, like create a pull request automatically after the push etc. See GitLab's options as an example.

My failed attempt to recreate this with git2go :

package main

import (
	git "github.com/libgit2/git2go/v34"
	log "github.com/sirupsen/logrus"
)

func main() {
	repo, err := git.OpenRepository("/home/ml/Projects/demo")
	if err != nil {
		log.Fatal(err)
	}
	remote, err := repo.Remotes.Lookup("origin")
	if err != nil {
		remote, err = repo.Remotes.Create("origin", repo.Path())
		if err != nil {
			log.Fatal(err)
		}
	}

	// ref
	ref, err := repo.Head()
	if err != nil {
		log.Fatal(err)
	}

	// Get the name
	branch := ref.Branch()
	branchName, err := branch.Name()
	if err != nil {
		log.Fatal(err)
	}

	if err := remote.Push([]string{"refs/heads/" + branchName}, &git.PushOptions{
		RemoteCallbacks: git.RemoteCallbacks{
			CredentialsCallback: func(url string, username_from_url string, allowed_types git.CredentialType) (*git.Credential, error) {
				return git.NewCredentialUserpassPlaintext("username", "pass")
			},
		},
		Headers: []string{"merge_request.create:true"},
	}); err != nil {
		log.Fatal(err)
	}
}

Is there a way to do this?