I went to: Text → Glyphs → and found the symbol. However, I can't get it from the window box to the artboard.
I've searched Google & YouTube, but cannot find the answer. How do I type in the Registered ® symbol in Inkscape?
Open the Glyphs panel (Text → Glyphs). Select a text element. Click on the glyph you want, and click the Append button in the bottom-right.
If you want it in your clipboard, double-click the glyph to add it to the text-field in the bottom left of the panel—you can copy it from there.