My react-native app needs to create a calendar event, it doesn't need to view, edit or delete event. I tried to use few react-native libraries which handle calendar but I needed to grant permissions for a calendar in each of them.
I have no knowledge of Objective C or Swift, but I would like to know if it is even possible in either native or react-native way. Every advice is very appreciated. Thanks!
Short answer is no. You do need to be granted permission to create a calendar event.
The Human Interface Guidelines section about requesting permissions
Users must grant permission for an app to access personal information, including the current location, calendar, contact information, reminders, and photos. Although people appreciate the convenience of using an app that has access to this information, they also expect to have control over their private data. For example, people like being able to automatically tag photos with their physical location or find nearby friends, but they also want the option to disable such features.
In the apple docs it specifies that you need to add an entry to the info.plist. This text is used when the permission is requested.
Important: If your iOS app links on or after iOS 10.0 and you need to access Calendar data, be sure to include the NSCalendarsUsageDescription key in your Info.plist file.
Your app will crash without this key added to the info.plist.
This is the case for native apps, so the same will apply for react-native.