Hello! I'm Manoel Barros, a Microsoft user just like you! I will do my best to help you.
If you are looking for a product to buy, you can go to your country's online store sites, such as Amazon or eBay, and search for "USB Fax modem".
Look for a product that has the specifications you want, and check operating system compatibility in the product description.
NOTE: be aware of ads that may advertise products that are often classified as PUP (Potentially Unwanted Products). Research any product advertised on the site before deciding to download and install it.
Let me know if your issue is resolved after running the troubleshootings!