How print job with CUPS and nodejs

Question

Dear after so many hours of configuration I reached the point that I do not understand why I can not print. I have a debian server with CUPS the idea is that from my API in NODEJS I can print a .pdf. Both the CUPS and NODE throw me the same error. {"version": "2.0", "statusCode": "client-error-bad-request", "id": 27221384, "operation-attributes-tag": {"attributes-charset": "utf-8", "attributes-natural-language": "en-us", "status-message": "No file in print request."}}. If I printed the test page from CUPS it works perfectly. Does anyone know if it is a code problem in NODEJS or a CUPS configuration?

my controller

    var ipp = require("ipp");
var printer = ipp.Printer("http://root:[email protected]:631/printers/EPSON_TM-T20II");
var fs = require("fs");
var document;

fs.readFile("C:\\filename.pdf", function(err, data) {
if (err) {
    console.log(err)
}

document = data;
});

var msg = {
    "operation-attributes-tag": {
        "requesting-user-name": "pos",
        "document-format": "application/pdf"
    },
    data: document };

printer.execute("Print-Job", msg, function(err, res) {
        console.log(err);
        console.log(JSON.stringify(res));
});

Answer 1

    fs.readFile("C:\\filename.pdf", function(err, data) {
if (err) {
    console.log(err)
} else {
    var msg = {
        "operation-attributes-tag": {
            "requesting-user-name": "pos",
            "document-format": "application/pdf"
        },
        data: data };

    printer.execute("Print-Job", msg, function(err, res) {
            console.log(err);
            console.log(JSON.stringify(res));
            return
    });
}