If you want to set your Favicon Go to Design Tab > Site Properties > Favicon > Choose File and select Show Favicon then click Save.
If you don't have favicon file that is in ".ico" format, you have to convert your image file to ".ico" first by using converter website. We suggest using https://www.icoconverter.com/ to convert it (You can use other converter site as well).
Click "Convert" then your file will be downloaded and saved.
You can name your file any name, but when you upload your file to RVsitebuilder, its name in the program will be renamed to "favicon.ico" automatically.