TYPO3 Core

Ok find the solution, the problem was in my Apache vconf, I have to change the rewrite directive with this :

    <IfModule mod_rewrite.c>
         # Enable URL rewriting
        RewriteEngine On
        RewriteRule ^(?:fileadmin/|typo3conf/|typo3temp/|uploads/) - [L]

        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteCond %{REQUEST_FILENAME} !-l
        RewriteCond %{REQUEST_URI} ^/typo3/.*$
        RewriteRule ^typo3/(.*)$ %{ENV:CWD}typo3/index.php [QSA,L]
    </IfModule>

It's because with Typo3 v11, Typo3 has rewrite rules for BE.

Look there : https://docs.typo3.org/c/typo3/cms-core/master/en-us/Changelog/11.0/Breaking-93048-BackendURLRewrites.html

And finally, I've found that it's not needed to do this in vconf because it's already in .htaccess but I in my case htaccess was disabled globally in my Apache conf. So I re-enable it and don't need the instruction above.