Anyone can invite you to one of their OurCal groups by sharing the invite member URL with you.
When you've received an OurCal invite URL:
- Tap the invite URL
- Tap Copy & Download
- You'll be redirected to download OurCal
- Open OurCal once downloaded
- In onboarding tap Paste & Join
- If you don’t see this then go back and click your invite link again