cb474 I can confirm. This typically occurs when the app developer has enabled Google's Play Integrity API for the app's Play Store entry, which bans the entry from being visible if you're running an OS that does not license Google Mobile Services. It also prevents you from installing it even if you open the Play Store entry from a URL.
It's one of the few times where you'll have to use Aurora Store to install the app. I tested it briefly and Airalo launches without complaints when installed from Aurora. You can contact the app developer and ask them to allow GrapheneOS users to install the app from Play Store.