How to update existing episerver forms records

Hi Team,

I have a registration page for which we have used episerver forms to save user details, now i want to create a profile block using MAI connector in which im fetching all the form submission data using below code:

_formDataRepository.GetSubmissionData(new FormIdentity(info.FormGuid, "en"),DateTime.Now.AddDays(-100),DateTime.Now).ToList();

but now i want to update the records with some changes in it, going through one of the link it was suggested to use below code 

var submissionStorage = _submissionStorageFactoryy.GetStorage(formIdentity);
submissionStorage.UpdateToStorage(args.FormSubmissionId, formIdentity, args.SubmissionData);

but im not sure how i can get the formSubmissionId. Is there a way to fetch the formsubmissionid using formIdentity.