How to use the jszip.JSZip function in jszip

function getDocxReportFromJSON(json, template) {
    let zip = new JSZip(templates[template]);
    let doc = new Docxtemplater();
    doc.loadZip(zip);

    //set the templateVariables
    doc.setData(json);

    try {
        // render the document (replace all occurences of tags.
        doc.render()
    } catch (error) {
        let e = {
            message: error.message,
            name: error.name,
            stack: error.stack,
            properties: error.properties
        }