Quick answer: Add the host through the platform's friends service and confirm their game is active. If it still does not appear, use the current Join Code instead.
- Join methods
- Platform friends list, Per-session Join Code
Mac App Store exception
That version does not support Game Center friends-list discovery. Official guidance says Mac App Store players need to join with a code.
Keep walking
Big Walk Join Codes and Session Passwords
Find and use a Big Walk Join Code safely, understand when a new code is generated, and keep the required session password private.
Cannot Join Friends in Big WalkUse the official Big Walk connection checklist for host readiness, version compatibility, Join Codes, internet, system clock, and full restarts.