directory NOT writeable even if proprietary is www-data

I have a fresh installation of queXF.

In the configuration check page, I have some errors related to permissions.

> Images directory NOT writeable - /images/

> Scans upload directory NOT writeable - /forms/

>HTPasswd file NOT writeable - /opt/quexf/password

I am confused because I set www-data as user and group of the all quexf folder with

># chown www-data:www-data -R quexf

I am also confused because I do not have a "forms" folder (I have "images" and "scans") and no htpasswd file in the quexf directory I downloaded.

Here are all permissions of the quexf folder.

/var/www/quexf$ ls -la
total 176
drwxr-xr-x 14 www-data www-data 4096 22 janv. 15:02 .
drwxr-xr-x 10 pwillaime pwillaime 168 22 janv. 15:15 ..
drwxrwxr-- 2 www-data www-data 4096 15 janv. 11:36 admin
-rwxrwxr-- 1 www-data www-data 25437 15 janv. 11:36 CHANGELOG
drwxrwxr-- 3 www-data www-data 54 15 janv. 11:36 client
-rwxrwxr-- 1 www-data www-data 10140 15 janv. 11:36 config.default.php
-rwxrwxr-- 1 www-data www-data 2596 22 janv. 14:31 config.inc.php
drwxrwxr-- 3 www-data www-data 179 15 janv. 11:36 css
drwxrwxr-- 2 www-data www-data 23 15 janv. 11:36 database
-rwxrwxr-- 1 www-data www-data 1788 15 janv. 11:36 db.inc.php
drwxrwxr-- 6 www-data www-data 331 15 janv. 11:36 doc
-rwxrwxr-- 1 www-data www-data 950 15 janv. 11:36 docker-compose.yml
drwxrwxr-- 2 www-data www-data 321 15 janv. 11:36 functions
drwxrwxrwx 2 www-data www-data 23 22 janv. 14:55 images
drwxrwxr-- 4 www-data www-data 82 15 janv. 11:36 include
-rwxrwxr-- 1 www-data www-data 1383 15 janv. 11:36 index.php
drwxrwxr-- 3 www-data www-data 186 15 janv. 11:36 js
-rwxrwxr-- 1 www-data www-data 1975 15 janv. 11:36 lang.inc.php
-rwxrwxr-- 1 www-data www-data 17987 15 janv. 11:36 licence.txt
drwxrwxr-- 20 www-data www-data 279 15 janv. 11:37 locale
-rwxrwxr-- 1 www-data www-data 5049 15 janv. 11:37 modifybox.php
-rwxrwxr-- 1 www-data www-data 2055 15 janv. 11:37 pagenote.php
-rwxrwxr-- 1 www-data www-data 1175 15 janv. 11:37 README.md
-rwxrwxr-- 1 www-data www-data 10270 15 janv. 11:37 review.php
drwxrwxr-- 2 www-data www-data 23 15 janv. 11:37 scans
-rwxrwxr-- 1 www-data www-data 1274 15 janv. 11:37 showmissingpage.php
-rwxrwxr-- 1 www-data www-data 4865 15 janv. 11:37 showpage.php
drwxrwxr-- 2 www-data www-data 88 15 janv. 11:37 upload
-rwxrwxr-- 1 www-data www-data 45383 15 janv. 11:37 verifyjs.php

(I am on debian stable)