How to add credits with Instagram nicknames?

How do you guys prefer to add credits that are not old-school first & last name, but Instagram nicknames?

It sometimes happens in music videos like this:

1. If on-screen credits contain such nicknames, then I should add them into "as" attribute, correct? If yes, then with @ at the start or without? Capitalized or lowercased?..
2. If there are no on-screen credits, but they are in a video description or a SNS post (which is common for music videos or advertisements), then... what? Is it preferable to add a person and leave the "as" attribute empty or fulfill it, too?