The Bitcoin symbol was added to the Unicode standard as ₿ (U+20BF). This shows up as a placeholder (empty box) in texts for me. What do you have to do so it will be shown in text, e.g. in the browser?
While the symbol was part of the Unicode 10.0 release, many fonts still don't have the symbol as part of their character set. You need to install a font that includes the symbol to make it show up.
One such font is
GNU Unifont Glyphs. After installing the package
unifont, the symbol shows up in the console and browser for me.
Corollary, many Linux distributions support inputting unicode symbols by typing
CTRL+SHIFT+U, followed by the symbol's designation
20bf offset by a space or