Anywhere text is accepted: Instagram bios, TikTok names, Discord, WhatsApp, gaming profiles and documents. The full Bold Italic alphabet is linked above.
What is the Bold Italic letter I?
It is the letter I rendered as the Unicode character ๐ฐ (code point U+1D470), part of the Bold Italic styled alphabet. It is a single character you can copy and paste anywhere.
How do I type ๐ฐ 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.