Error reason: The security entrance login has been enabled for the newly installed machine, and the newly installed machine will randomly have an 8-character security entrance name, which can also be modified in the panel settings. If you do not record or do not remember, you can use Solved in the following way
Solution: Enter the following command in the SSH terminal to solve
1. Check the panel entry: slemp default
2. Close the security entrance: slemp close_admin_path
Note: [Close the security entrance] will directly expose your panel login address to the Internet, which is very dangerous, please operate with caution