A. Check your internet connection by opening a web browser or another app that requires internet access. If your connection is weak or unstable, try switching from Wi-Fi to cellular data or vice versa. If the connection is fine, try resetting your network settings by going to Settings > General > Reset > Reset Network Settings. This will erase saved Wi-Fi passwords, so be prepared to re-enter them.
B. If the app continues to show errors despite a stable internet connection, try clearing the app's cache. Go to Settings > General > iPhone Storage > Blippar > Offload App. This will remove the app but keep its documents and data. Reinstall the app from the App Store.