How to configure Firestore without using .json file in Spring Boot?

I'm using Spring boot 2.7 and firebase-admin 7.1.0 dependency. I need to create a Firestore bean using Firestore credentials. I didn't find any way to set credentials using application.properties or by setting the environment variables. The only way I found was to get credentials using a .json file. I feel this is not secure.

@Value("${firebase.credential.path}")
private String credentialPath;

@Bean
public Firestore getFireStore() throws IOException {
    FileInputStream serviceAccount = null;
    try {
        serviceAccount = new FileInputStream(credentialPath);
        var credentials = GoogleCredentials.fromStream(serviceAccount);

        var options = FirestoreOptions.newBuilder()
                .setCredentials(credentials).build();

        return options.getService();
    } catch (IOException e) {
        log.error("Error in firebase authentication bean: {}", e.getMessage());
        return null;
    }
}

Is there any way to set credentials in the application.properties file or use environment variables if not Is it secure to take credentials from a separate .json file?