hmm no, unfortunately browser pdf viewer has no way to customize the name shown when using this technique.
you can try this that improves the mangled name a little more.
jsreport.renderAsync(request).then((res) => { var contentType = 'application/pdf' var dataView = new DataView(response) var blob var objectURL try { blob = new Blob([dataView], { type: contentType }) } catch (e) { if (e.name === 'InvalidStateError') { var byteArray = new Uint8Array(response) blob = new Blob([byteArray.buffer], { type: contentType }) } else { throw e } } objectURL = URL.createObjectURL(blob) var placeholder = document.getElementById('placeholder') var iframe = document.createElement('iframe') iframe.src = objectURL iframe.style.width = '100%' iframe.style.height = '100%' // clear placeholder while (placeholder.firstChild) { placeholder.removeChild(placeholder.firstChild); } placeholder.appendChild(iframe); Loading.hide() })