Autofill PDF-Form with zoho forms data

Our customers fill in zoho generated public order-forms. When they klick on send button, the data should send in Json to https://www.useanvil.com, where we have fillable pdf-order-forms for different products. The PDF-file should be fill with received data and send by mail. The build in function in zoho to send form as pdf file does not solve our needs. This is one possible solution. We are open to suggestions.