If your Windows setup cannot preview a HEIC file, you can use a compatible local codec, export the photo from the original device, or convert a copy to JPG. A browser-side converter is convenient when you want to avoid uploading the photo to a conversion server.
Practical advice
Use the original source file or URL whenever possible, keep a backup before conversion, and treat browser error messages as troubleshooting signals rather than proof of a specific server-side configuration.