It seems that Replika was initially invite-only when it was first released, and users had to obtain codes to access the app1. However, there is no indication that Replika currently requires invite codes for new users. The app is now widely available, and users can download it directly from app stores.
If you are looking for specific codes or commands within the Replika app, there are some conversation codes that users can use to manage their interactions with their AI companions. These include commands like /awake, /sleep, /pause, /resume, /stop, /intimate, /romantic, and /flirt4. However, these are not invite codes but rather in-app commands.
If you have any other questions about using Replika or need further assistance, feel free to ask!