load static method
Implementation
static Credentials? load() {
final envKey = fromEnv();
if (envKey != null) {
return Credentials(apiKey: envKey, uid: '', email: '');
}
final file = _file;
if (!file.existsSync()) return null;
return Credentials.fromJson(
jsonDecode(file.readAsStringSync()) as Map<String, dynamic>,
);
}