Facebook login only tied to email and not FB account?

[KatGamer]

I wasn't quite sure where to put this, please move it if necessary.

 

I use an iOS app called Migraine Buddy to track my migraines. I signed up for the app using Facebook Login.

 

Now, my Facebook account was tied to my email at myname@mydomain.com. About 10 years ago a friend gave me her website but held on to the domain name. She has become unreachable so mydomain.com is not working, and I registered mydomain.net. I changed my Facebook email address to the dot net.

 

Apparently, Migraine Buddy tied my account solely to my email address (at mydomain.com) and not to my Facebook account, because when I changed my FB email, I became unable to login to Migraine Buddy. Mydomain.com is gone now and I can't use it to recreate my old email address. (Facebook tells me I've already authorized the app, but then Migraine Buddy says it can't find my account.)

 

None of the other apps and websites I use with Facebook login have had a problem since I changed my FB email address, so this makes me think Migraine Buddy has something configured incorrectly. Is this the case and is there anything they can change so my account will link again?

 

I've been over it several times with their tech support, and despite me giving them a lot of my account information (my name, bday, the meds I take), they can't "prove" I'm me and so won't give me access to my account. (They asked if I could remember the date of my last migraine and I couldn't...hence why I was using the app to track them.) As a last-ditch attempt before I give up my data, I'm here to ask if there's anything they can change on their end so my account will work again.

[Seahorsepip Veteran]

The facebook API is commonly implemented in the following ways:

1. Facebook login API is used and user needs to login to facebook to login at the website
2. Facebook application API is used and user needs to login to facebook to share account details with the website, the user enters additiional info afterwards like a password and is registered on the site itself.
3. Some developer decided to do something totally different and made some frankenstein code...

Hoping that case 3 never happened I assume it's a matter of case 2 which means facebook was used to register on the site but not to login at the site. In this case there's a problem when your email is no longer accessible and you forgot the password, there's no longer a way to access your account 

 

But sites are known to help people access their accounts even in the case they lost access to their email account, their tech support will probably accept personal identifiable items like a passport to verify your account ownership.

 

Moderator note:

Since it's not exactly a development question but more a question about software and account management I moved the thread to general software support.

[KatGamer]

I already provided them with as much private information as I could, and no, they refuse to give me my account back.  thanks for your reply.