Since it's money and you're worried to let someone know your credentials/access your account, only way is to follow support's advice. Don't you have a family member with you that has a mobile, or a friend?

It has been an issue to me as well before. Such a hassle that I need to install the app first and open it everytime I log in my account on a web browser. They seem to not consider the idea of a user not having a phone.