No admin account after updating to macOS 13.2
Hello. I just had my MacBook Pro (2020 Intel) updated to macOS 13.2. While installing the update, the installation took longer than usual and so I decided to shut it down and reboot to continue. I repeated it several times but the installation speed did not improve. I then decided to go into Recovery System and reinstall macOS. When I was finally able to log back into my account, I noticed I could not do Time Machine backup. I cannot set up Time Machine backup in System settings as it requires an admin account. I then discovered that my account is now a standard account. I followed several guides here on Community discussions to try to create a second admin account but failed.
Is there any other way that I can add an admin account or do I need to just reset the whole computer?
Thank you!
MacBook Pro 13″, macOS 13.2