System maintainer area 

Accessing the system maintainer area 

The system maintainer area can only be accessed from the backend if:

• typo3/cms-install is installed. This system extension is optional.
• The currently logged in backend user has admin privileges and is a system maintainer.
• On systems in the application context "Production" the user has to reconfirm their login.

If the TYPO3 backend is not accessible you can access the "Install Tool", which features the Admin Tool modules provided by typo3/cms-install :

Accessing the Install Tools without TYPO3 Backend access 

On any TYPO3 installation with typo3/cms-install you can access the Install Tools by calling the following URL: https://example.org/typo3/index.php.

To prove that you have writing access to the file system where TYPO3 is installed you have to create a file in path var/transient/ENABLE_INSTALL_TOOL or config/ENABLE_INSTALL_TOOL. The file can be empty, TYPO3 has to have write access to the file. You can create it like this on:

touch config/ENABLE_INSTALL_TOOL

See also TYPO3 Explained, ENABLE_INSTALL_TOOL.

You must now enter the Install Tool password.

vendor/bin/typo3 install:password:set

typo3/sysext/core/bin/typo3 install:password:set

ddev typo3 install:password:set

Or you can set a new password by entering your desired password on the Install Tool login page, then copying the calculated hash:

Open file config/system/settings.php and adjust the Install tool password like so:

 <?php
 return [
     'BE' => [
-        'installToolPassword' => '$argon2i$v=19$m=65536,t=16,p=1$Z1BRbnZDdGx4T3pJVmpLVw$Bjhz+rSW1Bps5hIdXUBXrtlZ52E4Qx4lw4NU0MiEUyg',
+        'installToolPassword' => '$argon2i$v=19$m=65536,t=16,p=1$Z0tiZjVVdzN5VUEuLzhmYw$xTalKXJVMCALCO+0OklDt24Y/7NkffNc1bOeg2jo00I',
         'passwordHashing' => [
             'className' => 'TYPO3\\CMS\\Core\\Crypto\\PasswordHashing\\Argon2iPasswordHash',
             'options' => [],
         ],
     ],
 ];