How do you prompt in-game avatar editor?

How would you script a in-game avatar editor as used in the twenty one pilots event? Is there some service, is it a core ui, or is it just a function?

I wasn’t in the event but I suspect you mean these:
https://developer.roblox.com/en-us/api-reference/class/AvatarEditorService

https://developer.roblox.com/en-us/api-reference/class/AvatarEditorService