It is the letter G rendered as the Unicode character ๐ถ (code point U+1D676), part of the Monospace styled alphabet. It is a single character you can copy and paste anywhere.
How do I type ๐ถ on my phone or computer?
You do not type it from a keyboard; you copy it. Press the copy button above and paste it into any app. That is the whole point of Unicode styled letters.
Where can I use the Monospace G?
Anywhere text is accepted: Instagram bios, TikTok names, Discord, WhatsApp, gaming profiles and documents. The full Monospace alphabet is linked above.