Diễn đàn hỗ trợ Firefox

How can I do keyboard shortcut, "Text encoding options", then "Unicode". I have it on toolbars. Like on screnshot, I pint mouse, then I need to select Unicode, which is bothering. I am opening many many pages, which are always different than unicode.

I'd like to add Firefox to Adobe Dreamweaver for site design viewing. When searching Windows for Firefox.exe I don't see it in Program Files or Program Files (x86). Firefox is installed and used daily. Can someone tell me where it's located in Windows 10?