write method
Write a key-value pair to storage.
The key should be unique to the Amplify backend for which the
value applies to.
Adds a new key-value pair if the key does not currently exist, or updates the existing value if the key is present.
Implementation
@override
Future<void> write({required String key, required String value}) async {
await _init();
return _instance.write(key: key, value: value);
}