hi @Git-Dobou the support for docxHtml was introduced in jsreport 3.8.0, the playground uses jsreport 3.5.0 so it is not going to work there, you can check the jsreport version in playground by click this button
if i download your template and try it on my local with jsreport 3.8.0, it works.
we will soon update the playground so devs can share demos and code there. thanks