While some journals allow the practice of including two contact authors or corresponding authors, many journals do not. In your case, having two corresponding authors is a requirement for your paper. If you submit the manuscript with one corresponding author and explain in the paper or cover letter that you need to have two, you cannot really be sure whether the journal will allow this. If the journal does not allow, you will have to either go ahead with one corresponding author or withdraw your paper. The withdrawal process might be time-consuming and an additional hassle for you.To avoid this, you can send a pre-submission inquiry to the editor rather than submitting your manuscript. In the email, you can explain why you need two corresponding authors and two first authors, inquire if that is acceptable, and if so, how to submit your paper on the online system. If the editor gives a positive reply, you can go ahead and submit your paper. In case the editor replies that the journal policies do not allow this, you can submit your paper elsewhere directly without having to wait for the withdrawal process to complete.