If you want websites to think that you are using another browser, there is an add-on called “User-Agent Switcher and Manager” that changes your user agent. You can tell websites that you are using Google Chrome, when in reality you are using Firefox.
You can also choose from many versions of your desired browser and also let them think that you are on mobile, or macOS when you are in fact using Windows.
The add-on is available on all web browsers. Download it for Mozilla Firefox, Google Chrome, Microsoft Edge or Opera. Of course, you can also download it for Brave or Vivaldi. Just use the Chrome web store to download it for these browsers that have no store.