upgrade from 1.6 to 1.6.5 fail with the installto.sh script

[ewok2]

Hello
Download latest verstion 1.6.5 tar.gz
uncompress it
Going to the roundcube-1.6.5 directory
launching "./bin/installto.sh /var/www/roundcube/"

My conf :
Ubuntu 22.04
roundcube 1.6.0
php8.2

get error message :
PHP Fatal error: Uncaught Error: Call to undefined function mb_internal_encoding() in /home/user/roundcubemail-1.6.5/program/lib/Roundcube/bootstrap.php:86
Stack trace:
#0 /home/user/roundcubemail-1.6.5/program/include/iniset.php(78): require_once()
#1 /home/user/roundcubemail-1.6.5/program/include/clisetup.php(25): require_once('...')
#2 /home/user/roundcubemail-1.6.5/bin/installto.sh(23): require_once('...')
#3 {main}
thrown in /home/dimi/roundcubemail-1.6.5/program/lib/Roundcube/bootstrap.php on line 86

I have try to "install"
sudo apt-get install php8.2-mbstring
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
php8.2-mbstring is already the newest version (8.2.14-1+ubuntu22.04.1+deb.sury.org+1).

Any idea of the problem?
Do I try to upgrade manualy?

Thanks

[alecpl]

Ubuntu has ability to use different PHP version for CLI and Apache. Mybe you're not using the version you think you are.

Not Roundcube issue.

[ewok2]

Thanks it work with php8.3

Found a lot of "PHP Deprecated:" in error log.
do I need to fix it? or is it related to plugin not updated?