https://github.com/knative-extensions/eventing-github/blob/f34a508f89e52fe4ebd5eba5f630a0ae07d923cb/pkg/mtadapter/adapter.go#L111-L126

registerhandlerfor.go

// RegisterHandlerFor implements MTAdapter.
func (a *gitHubAdapter) RegisterHandlerFor(ctx context.Context, src *v1alpha1.GitHubSource) error {
	secretCli := a.secrGetter.Secrets(src.Namespace)
	secretToken, err := common.SecretFrom(ctx, secretCli, src.Spec.SecretToken.SecretKeyRef)
	if err != nil {
		return fmt.Errorf("reading token from Secret: %w", err)
	}

	logger := logging.FromContext(ctx)
	ceSrc := v1alpha1.GitHubEventSource(src.Spec.OwnerAndRepository)
	handler := common.NewHandler(a.ceClient, src.Status.SinkURI.String(), ceSrc, secretToken, logger)

	path := fmt.Sprintf("/%s/%s", src.Namespace, src.Name)
	a.router.Register(src.Name, src.Namespace, path, handler)

	return nil
}