Is there a way to convert .doc file to .docx file using docx library?

I’m doing a task which converting docx to html and the Mammoth library works well. However, I want to convert doc file to html but Mammoth doesn’t support it. I tried to convert doc to docx using docx library but it didn’t work
Here is the code that I tried

const docBuffer = await file.arrayBuffer();
const docString = new TextDecoder("utf-8").decode(docBuffer);

The result of docString is ��ࡱ� which is not what I’m expecting.
How can I get the string of doc file to pass it to the docx.Document method?

const docxFile = new docx.Document({
                                    sections: [
                                        {
                                            properties: {},
                                            children: [
                                                new docx.Paragraph({
                                                    children: [
                                                        new docx.TextRun({
                                                            text: "sadas" //here
                                                        })
                                                    ]
                                                })
                                            ]
                                        }
                                    ]
                                });