@Amanda300, if your browser believes, that your device has no camera, it means that it has no access to it. Maybe a long time ago, you got one of those requests "can Google / Firefox / Safari access your camera?" or your photos or location data etc and you clicked Refuse. Which is principally a sensible decision, but if you want to take the picture whilst being on the form on the browser, the browser needs that access. As would the app, if you download it.
If it's a phone, check the parameters, if it's a computer, check the system parameters. There is somewhere a chapter called "Authorisations " or "Confidentiality" or it may be in the chapter Photos. You may google it for your device. When you found it, give the browser permission to use the camera. When you are done, you may forbid access again.
If you are on a phone, the app is more comfortable to use. I use both, depending on purpose. It's not a big app in terms of storage, on my iphone and as a host with listings, it uses 177 MB, much less than newspaper apps or a few simple games. I can't remember even one crash of the app and it never crashed my phone (whilst my local newspaper app crashes daily.)