Unfortunately, free Zoom accounts are not eligible to be merged. If you were using your Drexel email for your free zoom.us account, it will have to be deleted before you can pickup your Drexel Zoom account. Here are instructions to do so.
Once the account is deleted, make sure you sign out of all your Zoom clients (desktop, mobile, etc) and navigate to drexel.zoom.us to login to your Drexel Zoom Account.