Instagram has three places you might want styled text. Each behaves differently, and picking the wrong place for a style leads to frustration.
Display name (the name under your handle)
Fancy text works here perfectly. This is where most stylish Instagram text lives — it renders on profiles, in DMs, in search results, and in tagged photos. The character limit is generous, so you have room to use even the wider Unicode styles. This is the safest place to experiment.
Bio (the short description)
Also works well, with one thing to watch: the bio has a 150-character limit, and Unicode-styled characters still count as one character each. The Wide style doesn’t double your count even though it looks twice as long. Mix styled headlines with plain-text explanations for the best readability.
Captions and comments
Works, but use sparingly. A caption with fancy styling throughout becomes hard to read, and worse — it becomes harder for Instagram to understand, which can affect how your post is recommended. A styled opening line over plain-text body text is the common best practice.