Open and read Word or PDF file in Node SDK

import * as fs from "fs";

const wordsApi = new WordsApi("####-####-####-####-####", "##################");
const fileName = "Input.docx";

const requestFileContent = fs.createReadStream(fs.readFileSync(
   fileName, 'utf8'));
const uploadDocumentRequest = new model.UploadFileRequest({
    fileContent: requestFileContent,
    path: fileName
});

wordsApi.uploadFile(uploadDocumentRequest)
.then((uploadDocumentRequestResult) => {
    console.log("Result of UploadDocumentRequest: ", uploadDocumentRequestResult);
    const requestParagraph = new model.ParagraphInsert({
        text: "Reading and writing to the file in the cloud occurs automatically."
    })
    const insertParagraphRequest = new model.InsertParagraphRequest({
        name: fileName,
        paragraph: requestParagraph
    });

    wordsApi.insertParagraph(insertParagraphRequest)
    .then((insertParagraphRequestResult) => {
        console.log("Result of InsertParagraphRequest: ", insertParagraphRequestResult);
        const downloadDocumentRequest = new model.DownloadFileRequest({
            path: fileName
        });

        wordsApi.downloadFile(downloadDocumentRequest)
        .then((downloadDocumentRequestResult) => {
            console.log("Result of DownloadDocumentRequest: ", downloadDocumentRequestResult);
        });
    });
});