I guarantee that a librarian would have helped you if you told them you didn’t have your phone on you.
I did tell the 1st librarian I did not have a phone. It’s what led up to green lighting my request to plugin.
I’ve run into this at other libraries because I do not carry my phone. Whenever I ask how to get online without a phone, the answer is to use their PCs (if they exist, and if they are open [as they are closed part of the day]). That’s it. There is no upstream support call. They apparently don’t even give feedback to management that someone was denied access for not having a phone.