a2pClient.headlessChromeFromHtml does not accept backslashes

[Andromeda227799]

Api2PdfClient a2pClient = new Api2PdfClient(api2PDFProperties.getApiKey());

String html = "String with backslash \ "

//below code breaks with a 400 error
String pdfURL = a2pClient
.headlessChromeFromHtml(html, true, filename, options)
.getPdf();