Instagram Recovery Options Don't Work When You've Lost Your Old Phone Number

I am writing because I can no longer access my Instagram account and I need help recovering my password. The account was registered only with a phone number that I have now lost, and there is no email address linked to the account. When I try to log in, Instagram asks for verification via the registered phone number, but I no longer have access to that number, so I cannot receive any verification code or recovery link and I am completely locked out of my account. I have tried the recovery options suggested in the app and Help Center, but they do not work for my situation because all of them require access to the old phone number. I am currently using Instagram on an iPhone 14 Pro, and I have been unable to access my account since around the middle of last year, so this problem has been ongoing for a long time without resolution. I kindly request your assistance to help me recover access to my account and reset my password, for example by verifying my identity through an alternative method and allowing me to update the phone number or add a new recovery option. I would like to regain access to my account and continue using your service without losing my data and contacts.