How to find email linked to username?

I really need to figure this out. I initially got lingq on mobile (I think I used google?) and now I need to sign in on the website to import something, but I forgot my passcode and cannot recover it as I do not know my email and there is no way to see this on the mobile app (for some reason). My user name is kaifasstromai (the current one I am using I created so I could communicate on the forums as the phone version has no such feature (that I am aware of). Could anyone help?