To enter the opencart admin panel, you need to add the specified key and parameter to the address bar in the browser, otherwise an attempt to enter the panel will be added. You can also add a check for filling in a hidden field, if it is filled in and the check of this field is enabled, it will be impossible to enter the panel even with the correct password.

Format:

/admin/index.php?route=common/login&secret_key=secret
/admin/index.php?secret_key=secret
/admin/?secret_key=secret