The person or organisation that invited you to use our app should have sent you a PIN code. Please contact them to make sure they've created an account for you, and to send you a PIN code.
Make sure you allow receiving push notifications for our app. When you first installed the app, we've asked you to allow receiving push notifications.
To double check and/or to change your settings, go to your Settings app, and choose Notifications.
Then, find our app and make sure 'Allow notifications' is enabled.
Other fixes could be: turn off adaptive battery on android or third-party battery-saving apps (which disable autostart).
Some firewalls may block access to our app.
If you're on a WiFi, try using your 4G/5G connection to use our app.
If that still doesn't work, please contact us (see bottom of this page).
Like push messages, our app needs your permission to use the camera.
In order to change your camera access, go to Settings and choose Privacy -> Camera.
Then find our app and modify access to the camera.