Get Terms from Term Set Group Name using JSOM

$(document).ready(function()
                  {
    SP.SOD.executeFunc('sp.js', 'SP.ClientContext', function()
    {
        var scriptbase = _spPageContextInfo.webServerRelativeUrl + "/_layouts/15/";
        $.getScript(scriptbase + "SP.Taxonomy.js", getTerms);
    });
});

function getTerms()
{
    var clientContext = SP.ClientContext.get_current();
    var taxonomySession = SP.Taxonomy.TaxonomySession.getTaxonomySession(clientContext);
    var termStores = taxonomySession.get_termStores();
    //Name of the Term Store from which to get the Terms.
    var termStore = termStores.getByName("Taxonomy_l7bKEIowEUW0cMnRVLd7UA==");
    //GUID of Term Set from which to get the Terms.
    var termSet = termStore.getTermSet("1f87ca28-82c0-4808-a766-5225504cec64");
    var terms = termSet.getAllTerms();
    clientContext.load(terms);
    clientContext.executeQueryAsync(function onSuccess() {
        var enumerator = terms.getEnumerator();
        while (enumerator.moveNext()) {
            var spTerm = enumerator.get_current();
            var name = spTerm.get_name();
            var id = spTerm.get_id()._m_guidString$p$0;
        }
    }, function onFailure(args) {
        //alert('Error: '+args.get_message());
    });
}