mediawiki does not find mysql

After a reinstall of Ubuntu 22.10 and copy of backup to /var/www/html/ of mediawiki-1.38.4, reinstall of PHP8 and enabling of mbstring, intl and xml in a webbrowser to localhost/mediawiki-1.38.4 the browser shows

[bbaec1736a578888733dc2ec] /mediawiki-1.38.4/index.php/ InvalidArgumentException: Wikimedia\Rdbms\Database::getClass no viable database extension found for type 'mysql'

Backtrace:

from /var/www/html/mediawiki-1.38.4/includes/libs/rdbms/database/Database.php(491)
#0 /var/www/html/mediawiki-1.38.4/includes/libs/rdbms/database/Database.php(436): Wikimedia\Rdbms\Database::getClass()
...
#32 /var/www/html/mediawiki-1.38.4/index.php(44): require(string)

index.php contains the following where line 44 is the line starting with require

define( 'MW_ENTRY_POINT', 'index' );

// Bail on old versions of PHP, or if composer has not been run yet to install
// dependencies. Using dirname( __FILE__ ) here because __DIR__ is PHP5.3+.
// phpcs:ignore MediaWiki.Usage.DirUsage.FunctionFound
require_once dirname( __FILE__ ) . '/includes/PHPVersionCheck.php';
wfEntryPointCheck( 'html', dirname( $_SERVER['SCRIPT_NAME'] ) );

require __DIR__ . '/includes/WebStart.php';
wfIndexMain();

function wfIndexMain() {
    // @todo Deprecate global $mediaWiki
    // phpcs:ignore MediaWiki.NamingConventions.ValidGlobalName.allowedPrefix
    global $mediaWiki;
    $mediaWiki = new MediaWiki();
    $mediaWiki->run();
}

How shall I proceed to find and correct the error?

Even sillier answer. MySql was not installed, makes me really ashamed. Thanks for your question, it directed me to the solution.