Unable to login - 2FA

Hi, I'm having problems logging in to my work account (which is associated with a different email address than this one). The issue seems to be the 2FA since I am able to enter my username and password without an problem. Once I do that I am directed to enter a 6-digit code from an authenticator app, but I don't believe I have ever set up 2FA or synced my Box account to an authenticator app. Sometimes, after entering my name and password, I am instead directed to enter my phone number. But, when I do so and hit Submit, the phone number I typed in disappears and nothing happens. Please help me resolve this problem!