mailboxes disappeared MacOS 15.5 Sequoia - How do I recover them?

I am running Sequoia 15.5 on a MacBook Air. All of my mailboxes have disappeared. I have seen that in previous MacOS versions they were stored in My Home>Library>Mail>V10. Unfortunately I can't get past Home>Library> because of access limits. I have tried command key/. bypass but I can't get access to the Mail and V10 folders so I can't restore V10 with Time Machine. How can I recover my mailboxes? Suggestions would be appreciated