Locked out of Apple account
So recently I tried updating one of my apps and it will not allow me to because it said my account has been locked for security reasons, which are unknown to me. I’ve tried having it emailed to my email my Apple username is connected through, no email. I’ve checked and the email is correct. Tried getting through using my birthday, which I’ve entered multiple times and it says the birthday is incorrect. I’ve tried my security question, also says is incorrect. I’ve never had this issue before and I’ve had the same phone for 2 years now. Nothing has been changed and it’s super frustrating. Any suggestions on what I can do?
iPhone 11, iOS 14