meesenger4j how to handle request from diffrent facbook app - spring-boot

Question

I would like to create a rest api that handle user messenger app credential (token,appsecret,verifToken) as parameters instead of define them as env variable.
So that more than one user (facebook app) can subscribe to my rest api throw messenger webhook .
Is that possible?
First, i tried with credential in app.prop and injected the Messenger4j client in Restcontroller constructor and it works like charm (webhook call, conversation...).
Now is it possible to do that for more than one facebook app to communicate with my rest api :
the logic will be:
first connect(accesToken,appSecret) to our backend and save app credential and get response with myBackendApiUrl and generate verifToken.
#RequestMapping(value = "/connect", method = RequestMethod.POST)
public ResponseEntity<String> connect(#RequestParam final String pageAccessToken,
#RequestParam final String appSecret,
) {
logger.debug(" connect ");
try {
logger.debug("********");
//Messenger messenger = Messenger.create(pageAccessToken, appSecret, verifyToken).;
String verifyToken= UUID.randomUUID().toString();
MessengerCredentials msgerCred = new MessengerCredentials(pageAccessToken,appSecret,verifyToken);
messengerCredentialRepo.save(msgerCred);
return ResponseEntity.ok("webhookurl: myurl"+ "verifToken:"+verifyToken);
} catch (Exception e) {
logger.warn("failed to connect", e.getMessage());
return ResponseEntity.status(HttpStatus.FORBIDDEN).body(e.getMessage());
}
}
After that the user should configure messenger app webhook with url and verif token recived in the response body method connect() to avonke the webhook handler and this is how it may be like
#RequestMapping(method = RequestMethod.GET)
public ResponseEntity<String> verifyWebhook(#RequestParam(MODE_REQUEST_PARAM_NAME) final String mode,
#RequestParam(CHALLENGE_REQUEST_PARAM_NAME) final String challenge,
#RequestParam(VERIFY_TOKEN_REQUEST_PARAM_NAME) final String verifyToken
) {
logger.debug("Received Webhook verification request - mode: {} | verifyToken: {} | challenge: {}", mode, verifyToken, challenge);
try {
logger.debug("********");
this.messenger.verifyWebhook(mode, verifyToken);
return ResponseEntity.ok(challenge);
} catch (MessengerVerificationException e) {
logger.warn("Webhook verification failed: {}", e.getMessage());
return ResponseEntity.status(HttpStatus.FORBIDDEN).body(e.getMessage());
}
}
Is that possible?!
and how can i deal with post handler to handel users events it my Messenger4j bean not instanciate yet.