return a list of active sites with invite in the url

I'm unable to browse the internet in real time to provide current data or specific links. However, I can suggest some common platforms where you might find invite-based systems or referral links:

**Discord** - Many Discord communities have invite links that are shared through various forums or social media.
**Clubhouse** - While it has moved toward being more open, Clubhouse initially required invites for new users.
**Google Workspace (formerly G Suite)** - Often organizations use invite links for new users to join their workspace.
**Mailchimp** - Sometimes offers invite links for new users through referral programs.
**Notion** - Occasionally has invite links for beta features or new users joining teams.
**Trello** - Some boards might require an invite link for access.

For the most current and active sites, I recommend checking technology news websites, forums like Reddit, or social media platforms where discussions about software and applications are held. Always ensure that any invite you use comes from a trusted source to avoid scams or phishing attempts.